2-(heterocyclylthio) carbapenem derivatives, their preparation and their use as antibiotics

ABSTRACT

Compounds of formula (I): ##STR1## in which R a  is a group of formula (II): ##STR2## where one of R&#39; is a bond to the remainder of the compound, one more of R&#39; is R 2  and the others of R&#39; are all hydrogen, R 1  is hydrogen or methyl, R 2  is hydrogen, optionally substituted alkyl, halogen, hydroxy, alkoxy, amino, alkanoylamino, alkanoyloxy, alkanoyl, carboxy, alkoxycarbonyl, cyano, --S(O) j  R 9  where j is 0, 1 or 2 and R 9  is alkyl, or --CONR 6  R 7  which is optionally substituted carbamoyl or heterocyclyl-carbonyl, --NR 3  R 4  is optionally substituted amino or heterocyclic, and --COOR 5  is carboxy, --COO - , --COOM x , where M is a cation and x is the reciprocal of the valence of the cation M or protected carboxy and, where --COOR 5  is carboxy, --COOM x  or protected carboxy, the compound of formula (I) also contains an anion; l, m and n are independently 0, 1, 2 or 3, provided that (m+n) is an integer from 2 to 6; p is 0, 1 or 2; Y is a single bond, oxygen, sulfur or ##STR3## wherein R 8  is hydrogen, alkyl or alkanoyl, and pharmaceutically acceptable salts and esters thereof. Such compounds are useful as antibiotics.

This is a division of application Ser. No. 07/540,878 filed Jun. 20,1990, now U.S. Pat. No. 5,104,867, issued Apr. 14, 1992, which is acontinuation of application Ser. No. 07/332,884 filed Apr. 3, 1989, nowabandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a series of new carbapenem compounds,to methods using these compounds and to compositions containing thesecompounds, and provides processes for preparing these compounds.

2. Background Information

The penicillins form a well known class of antibiotics, which have foundconsiderable use in human and animal therapy for many years. Chemically,the penicillins have in common a β-lactam structure, commonly referredto as "penam", which may be represented by the following formula:##STR4##

However, although the penicillins still form a valuable weapon in thepharmaceutical armory, the development of new, and oftenpenicillin-resistant, strains of pathogenic bacteria has increasinglymade it necessary to search for new types of antibiotic.

In recent years, great interest has been shown in compounds having acarbapenem structure, that is compounds having a carbon atom in place ofthe sulfur atom at the 1-position and having a double bond between thecarbon atoms in the 2- and 3-positions of the basic penam structure. Thecarbapenem structure may be represented by the following formula:##STR5##

These penam and carbapenem structures form the basis for thesemi-systematic nomenclature of the penicillin derivatives in accordancewith the recommendations of the International Union of Pure and AppliedChemistry (IUPAC), and this nomenclature is generally accepted by thoseskilled in the art throughout the world and is used herein. Thenumbering system employed herein is that illustrated on the aboveformula (B).

Of the known carbapenem derivatives, the best known is a compound called"thienamycin", whose semi-systematic name is2-(2-aminoethylthio)-6-(1-hydroxyethyl)carbapen-2-em-3-carboxylic acid.Although thienamycin is known to have remarkably potent and broadantibacterial activity, its chemical stability in the human body ispoor, which restricts its practical use. Various attempts have,therefore, been made to modify the chemical structure of thienamycin inorder to improve its chemical stability whilst maintaining or improvingits superior activity, but there is still a continuing need to developfurther carbapenem antibiotics with improved properties.

The present invention provides a new group of carbapenem derivativeswhich possess superior absorption and metabolic stability (as evidencedby improved recovery rates in the urine), as well as a broadantibacterial spectrum and low toxicity. The invention also providessynthetic processes for the preparation of the new carbapenemderivatives, as well as pharmaceutical compositions comprising the saidderivatives suitable for human and animal administration.

Of the prior art known to us, the following are believed to be theclosest:

U.S. Pat. No. 4,640,799 and No. 4,665,170 disclose carbapenem compoundsin which there is a group --S--A--N⁺ at the 2-position. "A" can bevarious groups, and N⁺ represents a quaternized nitrogen-containingheterocyclic group attached to A through its quaternary nitrogen atom.These compounds differ from those of the present invention in that,where the compounds of the present invention contain a quaternizednitrogen-containing heterocyclic group having a quaternary nitrogenatom, this is not attached to the rest of the molecule via thequaternary nitrogen atom, but is attached via a carbon atom of theheterocyclic group.

European Patent Specification No. 126 587 discloses a series ofcarbapenem compounds having a pyrrolidinylthio group at the 2-position.These differ from the compounds of the present invention which arequaternary nitrogen compounds in that these prior art compounds are notquaternary nitrogen compounds and they differ from the non-quaternizedcompounds of the present invention in the nature of the substituents onthe heterocyclic ring. Certain of the compounds disclosed in this priorart may have good activity, but they are believed to be less wellabsorbed in vivo than are the compounds of the present invention.

BRIEF SUMMARY OF INVENTION

The compounds of the present invention may be represented by the formula(I): ##STR6## in which: R^(a) represents a group of formula (II):##STR7## or a group of formula (III): ##STR8## and in which: one of thesymbols R' represents a bond to the remainder of the compound of formula(I), in said group of formula (II) one of the symbols R' is R² and inboth said groups of formula (II) and (III) the others of the symbols R'all represent hydrogen atoms;

where R^(a) represents said group of formula (II), then R¹ represents ahydrogen atom or a methyl group, or, where R^(a) represents said groupof formula (III), then R¹ represents a methyl group;

R² represents a hydrogen atom, a C₁ -C₆ alkyl group, a C₁ -C₆ alkylgroup having at least one substituent selected from the group consistingof substituents (a), a halogen atom, a hydroxy group, a C₁ -C₆ alkoxygroup, an amino group, a C₁ -C₆ alkanoylamino group, a C₁ -C₆alkanoyloxy group, a C₁ -C₆ alkanoyl group, a carboxy group, a C₂ -C₇alkoxycarbonyl group, a cyano group, a group of formula --S(O)_(j) R⁹

wherein j is zero or an integer 1 or 2 and R⁹ represents a C₁ -C₆ alkylgroup;

or a group of formula --CONR⁶ R⁷

wherein R⁶ and R⁷ are independently selected from the group consistingof hydrogen atoms, C₁ -C₆ alkyl groups, C₃ -C₆ cycloalkyl groups, C₂ -C₆alkenyl groups, C₂ -C₆ alkynyl groups and C₁ -C₆ alkyl groups having atleast one substituent selected from the group consisting of substituents(a), or R⁶ and R⁷ together represent a C₁ -C₆ alkylene group of a C₁ -C₆alkylene group whose carbon chain is interrupted by an oxygen or sulfuratom or by a group of formula ##STR9## wherein R⁸ represents a hydrogenatom, a C₁ -C₆ alkyl group or a C₁ -C₆ alkanoyl group,

or R⁶ and R⁷ together represent said alkylene group having at least onesubstituent selected from the group consisting of substituents (b),defined below;

R^(2a) represents a hydrogen atom, a C₁ -C₆ alkyl group of a C₁ -C₆alkanoyl group;

R³ and R⁴ are independently selected from the group consisting of C₁ -C₆alkyl groups, C₂ -C₆ alkenyl groups, C₂ -C₆ alkynyl groups, aralkylgroups where the alkyl part is C₁ -C₃ alkyl and the aryl part is C₆ -C₁₀carbocyclic aromatic which is unsubstituted or has at least onesubstituent selected from the group consisting of substituents (c),cycloalkylalkyl groups where the alkyl part is C₁ -C₃ alkyl and thecycloalkyl part is C₃ -C₆, and C₁ -C₆ alkyl groups having at least onesubstituent selected from the group consisting of substituents (a), orone of R³ and R⁴, together with R², represents a C₁ -C₆ alkylene groupor a C₁ -C₆ alkylene group whose carbon chain is interrupted by anoxygen or sulfur atom or by a group of formula ##STR10## wherein R⁸ isas defined above, or one of R³ and R⁴, together with R², represents saidalkylene group having at least one substituent selected from the groupconsisting of substituents (b), defined below; and

--COOR⁵ represents a carboxy group, a group of formula --COO⁻, a groupof formula --COOM_(x), where M is a cation and x is the reciprocal ofthe valence of the cation M, or a protected carboxy group and, where--COOR⁵ represents a carboxy group, a group of formula --COOM_(x) or aprotected carboxy group, the compound of formula (I) also contains ananion;

l, m and n are independently zero, or an integer from 1 to 3, providedat (m+n) is an integer from 2 to 6;

p is zero or the integer 1 or 2;

Y represents a single bond, an oxygen atom, a sulfur atom or a group offormula ##STR11## wherein R⁸ is as defined above, substituents (a)

hydroxy groups, cyano groups, carbamoyloxy groups, azido groups, carboxygroups, nitro groups, oxo groups, halogen atoms, C₁ -C₆ alkoxy groups,C₁ -C₆ alkanoyl groups, C₁ -C₆ alkanoyloxy groups, C₁ -C₆ alkanoylaminogroups, C₂ -C₇ alkoxycarbonyl groups, groups of formula --NR¹⁰ R¹¹ and--CONR¹² R¹³

in which R¹⁰, R¹¹, R¹² and R¹³ are independently selected from the groupconsisting of hydrogen atoms, C₁ -C₆ alkyl groups and C₁ -C₆ alkanoylgroups,

groups of formula --SO₂ NR¹⁴ R¹⁵ and --S(O)_(k) R¹⁶

wherein R¹⁴, R¹⁵ and R¹⁶ are independently selected from the groupconsisting of C₁ -C₆ alkyl groups and k is zero or an integer 1 or 2,and

groups of formula --NHSO₂ R¹⁷, --N═CR¹⁸ NR¹⁹ R²⁰, --N═CR²¹ CR²² ═NR²³and --(═NH)NR²⁴ R²⁵

wherein R¹⁷ to R²⁵ are independently selected from the group consistingof hydrogen atoms and C₁ -C₆ alkyl groups;

substituents (b)

hydroxy groups, cyano groups, carbamoyl groups, oxo groups, halogenatoms, C₁ -C₆ alkyl groups and C₁ -C₆ alkoxy groups;

substituents (c)

C₁ -C₄ alkyl groups, C₁ -C₄ alkoxy groups, C₁ -C₄ haloalkyl groups, C₁-C₃ alkylenedioxy groups, halogen atoms, cyano groups and nitro groups;

and pharmaceutically acceptable salts and esters thereof.

The invention also provides a pharmaceutical composition comprising aneffective amount of an antibiotic in admixture with a pharmaceuticallyacceptable carrier or diluent, wherein the antibiotic is at least onecompound selected from the group consisting of compounds of formula (I)and pharmaceutically acceptable salts and esters thereof.

The invention still further provides a method for the treatment orprevention of microbial infection by the administration to a mammal,which may be human, of an effective amount of an antibiotic, wherein theantibiotic is at least one compound selected from the group consistingof compounds of formula (I) and pharmaceutically acceptable salts andesters thereof.

The invention also provides processes for preparing the compounds of thepresent invention, which are described in more detail hereinafter.

DETAILED DESCRIPTION OF INVENTION

In the compounds of the present invention, where R² R^(2a), R³, R⁴, R⁶,R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹, R²⁰, R²¹,R²², R²³, R²⁴, R²⁵ or substituent (b) represents an alkyl group, thismay be a straight or branched chain alkyl group containing from 1 to 6carbon atoms, and examples include the methyl, ethyl, propyl, isopropyl,butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, 2-methylbutyl,hexyl, isohexyl and 2-methylpentyl groups, of which the methyl, ethyl,propyl and butyl groups are preferred, the methyl group generally beingmost preferred.

In the case of R² and R^(2a), the most preferred of the unsubstitutedalkyl groups is the methyl group. In the case of R³ and R⁴, the mostpreferred of the unsubstituted alkyl groups are the methyl and ethylgroups, the methyl group being preferred of these. In the case of R⁶ andR⁷, the most preferred of the unsubstituted alkyl groups are the methyl,ethyl and isopropyl groups, the methyl and ethyl groups being especiallypreferred of these.

Where R² R^(2a), R⁸, R¹⁰, R¹¹, R¹², R¹³ or substituent (a) represents analkanoyl group, this may be a straight or branched chain alkanoyl groupcontaining from 1 to 6 carbon atoms, and examples include the formyl,acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyland hexanoyl groups, of which the formyl and acetyl groups are morepreferred.

Where R² or substituent (a) represents an alkanoylamino group, this maybe a straight or branched chain alkanoylamino group containing from 1 to6 carbon atoms, and examples include the formamido, acetamido,propionamido, butyramido, isobutyramido, valerylamino, isovalerylamino,pivaloylamino and hexanoylamino groups, of which the acetamido group ismore preferred.

Where R² or substituent (a) represents an alkanoyloxy group, this may bea straight or branched chain alkanoyloxy group containing from 1 to 6carbon atoms, and examples include the formyloxy, acetoxy, propionyloxy,butyryloxy, isobutyryloxy, valeryloxy, isovaleryloxy, pivaloyloxy andhexanoyloxy groups, of which the acetoxy, propionyloxy, butyryloxy,isobutyryloxy and pivaloyloxy groups are more preferred, and the acetoxygroup is most preferred.

Where R² or substituent (a) or (b) represents a halogen atom, this maybe a fluorine, chlorine, iodine or bromine atom, of which the fluorine,chlorine and bromine atoms are preferred, the fluorine and chlorineatoms being most preferred.

Where R² or substituent (a) or (b) represents an alkoxy group, this maybe a straight or branched chain alkoxy group containing from 1 to 6carbon atoms, and examples include the methoxy, ethoxy, propoxy,isopropoxy, butoxy, isobutoxy, sec-butoxy, t-butoxy, pentyloxy,isopentyloxy, 2-methylbutoxy, hexyloxy, isohexyloxy and2-methylpentyloxy groups, of which the methoxy, ethoxy, propoxy andbutoxy groups are preferred, the methoxy group generally being mostpreferred.

Where R² or substituent (a) represents an alkoxy-carbonyl group, thismay be a straight or branched chain alkoxy group containing, in total,from 2 to 7 carbon atoms, including the carbon atom of the carbonylgroup (i.e. the alkoxy part contains from 1 to 6 carbon atoms), andexamples include the methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl,isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl,sec-butoxycarbonyl, t-butoxycarbonyl, pentyloxycarbonyl,isopentyloxycarbonyl, 2-methylbutoxycarbonyl, hexyloxycarbonyl,isohexyloxycarbonyl and 2-methylpentyloxycarbonyl groups, of which themethoxycarbonyl and ethoxycarbonyl groups are most preferred.

Where R² represents a group of formula --S(O)_(j) R⁹, when j is 0, thegroup is an alkylthio group, when j is 1, the group is an alkylsulfinylgroup, and, when j is 2, the group is an alkylsulfonyl group. The alkylparts of these groups may be as already exemplified, and specificexamples of these groups include the methylthio, ethylthio, propylthio,isopropylthio, butylthio, isobutylthio, sec-butylthio, t-butylthio,pentylthio, isopentylthio, 2-methylbutylthio, hexylthio, isohexylthio,2-methylpentylthio, methylsulfinyl, ethylsulfinyl, propylsulfinyl,isopropylsulfinyl, butylsulfinyl, isobutylsulfinyl, sec-butylsulfinyl,t-butylsulfinyl, pentylsulfinyl, isopentylsulfinyl,2-methylbutylsulfinyl, hexylsulfinyl, isohexylsulfinyl,2-methylpentylsulfinyl, methylsulfonyl, ethylsulfonyl, propylsulfonyl,isopropylsulfonyl, butylsulfonyl, isobutylsulfonyl, sec-butylsulfonyl,t-butylsulfonyl, pentylsulfonyl, isopentylsulfonyl,2-methylbutylsulfonyl, hexylsulfonyl, isohexylsulfonyl and2-methylpentylsulfonyl groups, of which the methylthio, methylsulfinyland methylsulfonyl groups are most preferred.

Where R⁶ and/or R⁷ represents a cycloalkyl group, this has from 3 to 6ring carbon atoms, and examples include the cyclopropyl, cyclobutyl,cyclopentyl and cyclohexyl groups, of which the cyclopropyl, cyclopentyland cyclohexyl groups are more preferred and the cyclopropyl group ismost preferred.

Where R³, R⁴, R⁶ or R⁷ represents an alkenyl group, this has from 2 to 6carbon atoms and may be a straight or branched chain group. Examplesinclude the vinyl, 1-propenyl, allyl, isopropenyl, methallyl, 1-butenyl,2-butenyl, 3-butenyl, 2-propylallyl, 1-pentenyl, 2-pentenyl, 3-pentenyl,4-pentenyl, 1-butylvinyl, 2-methyl-3-pentenyl, 4-methyl-3-pentenyl,1-methyl-4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl,5-hexenyl, 3-methyl-1-butenyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl,3-methyl-1-pentenyl, 3-methyl-2-pentenyl, 3-methyl-3-pentenyl,3-methyl-4-pentenyl and 3-methyl-1-hexenyl groups, of which the allyl,butenyl and pentenyl groups are preferred and the allyl group is mostpreferred.

Where R³, R⁴, R⁶ or R⁷ represents an alkynyl group, this has from 2 to 6carbon atoms and may be a straight or branched chain group. Examplesinclude the ethynyl, 1-propynyl, 2-propynyl (i.e. propargyl), 1-butynyl,2-butynyl, 3-butynyl, 1-methyl-2-butynyl, 1-pentynyl, 2-pentynyl,3-pentynyl, 4-pentynyl, 1-methyl-2-pentynyl, 1-methyl-3-pentynyl,1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl,3-methyl-1-butynyl, 3-methyl-2-butynyl, 3-methyl-3-butynyl,3-methyl-1-pentynyl, 3-methyl-2-pentynyl, 3-methyl-3-pentynyl,3-methyl-4-pentynyl and 3-methyl-1-hexynyl groups, of which thepropargyl, butynyl and pentynyl groups are preferred and the propargylgroup is most preferred.

Where R³ or R⁴ represents an aralkyl group, the alkyl part is a C₁ -C₃alkyl group and the aryl part is a C₆ -C₁₀ carbocyclic aromatic groupwhich may be substituted or unsubstituted and, if substituted, has atleast one substituent selected from the group consisting of substituents(c) defined above and exemplified below. However, the unsubstitutedgroups are preferred. Examples of the alkyl parts of such aralkyl groups(which may be straight or branched chain groups) include the methyl,ethyl, propyl and isopropyl groups, of which the methyl and ethyl groupsare preferred. Examples of the aryl parts include the phenyl andnaphthyl (1- and 2-naphthyl) groups, of which the phenyl group ispreferred. Examples of such aralkyl groups include the benzyl,phenethyl, 1-phenylethyl, 3-phenylpropyl, 2-phenylpropyl,1-naphthylmethyl, 2-naphthylmethyl, 2-(1-naphthyl)ethyl and2-(2-naphthyl)ethyl groups, of which the benzyl or phenethyl groups arepreferred and the benzyl group is most preferred.

Where R³ or R⁴ represents a cycloalkylalkyl group, the alkyl part is aC₁ -C₃ alkyl group and the cycloalkyl part is a C₃ -C₆ cycloalkyl group.Examples of such alkyl groups are as given above in relation to thealkyl parts of aralkyl groups, and examples of such cycloalkyl groupsare as given above in relation to the same groups which may berepresented by R³ and R⁴. In this case, preferred alkyl parts are themethyl and ethyl, especially methyl, groups and preferred cycloalkylgroups are the cyclopropyl, cyclopentyl and cyclohexyl groups, of whichthe cyclopentyl and cyclohexyl groups are most preferred. Examples ofsuch cycloalkylalkyl groups include the cyclopropylmethyl,cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl,2-cyclopropylethyl, 2-cyclobutylethyl, 2-cyclopentylethyl,2-cyclohexylethyl, 1-cyclopropylethyl, 1-cyclobutylethyl,1-cyclopentylethyl, 1-cyclohexylethyl, 2-cyclopropylpropyl,2-cyclobutylpropyl, 2-cyclopentylpropyl, 2-cyclohexylpropyl,1-cyclopropylpropyl, 1-cyclobutylpropyl, 1-cyclopentylpropyl,1-cyclohexylpropyl, 3-cyclopropylpropyl, 3-cyclobutylpropyl,3-cyclopentylpropyl, 3-cyclohexylpropyl, 1-methyl-1-cyclopropylethyl,1-methyl-1-cyclobutylethyl, 1-methyl-1-cyclopentylethyl and1-methyl-1-cyclohexylethyl groups, of which the cyclopropylmethyl,cyclopentylmethyl, cyclohexylmethyl and 2-cyclopropylethyl groups arepreferred and the cyclopropylmethyl, cyclopentylmethyl andcyclohexylmethyl groups are most preferred.

Where either R³ or R⁴, taken together with R², represents an alkylenegroup which may contain an oxygen or sulfur atom or a group of formula##STR12## (wherein R⁸ represents a hydrogen atom, an alkyl group or analkanoyl group), it contains from 1 to 6 carbon atoms in the chain andmay, for example, be a group of formula --CH₂ --, --(CH₂)₂ --, --(CH₂)₃--, --(CH₂)₄ --, --(CH₂)₅ --, --(CH₂)₆ --, --(CH₂)₂ O--, --(CH₂)₂ OCH₂--, --CH₂ OCH₂ --, --(CH₂)₂ O(CH₂)₂ --, --(CH₂)₃ O(CH₂)₂ --, --(CH₂)₃O(CH₂)₃ --, --CH₂ NR⁸ --, --(CH₂)₂ NR⁸ --, --CH₂ NR⁸ CH₂ --, --(CH₂)₂NR⁸ CH₂ --, (CH₂)₂ NR⁸ (CH₂)₂ --, --CH₂ S--, --(CH₂)₂ S--, --CH₂ SCH₂--, --CH₂)₂ SCH₂ -- or --(CH₂)₂ S(CH₂)₂ --, and is more preferably agroup of formula --CH₂ --, --(CH₂)₂ --, --(CH₂)₃ --, --(CH₂)₄ --,--(CH₂)₅ --, --(CH₂)₂ O--, --(CH₂)₂ OCH₂ --, --(CH₂)₂ O(CH₂)₂ --,--(CH₂)₂ NR⁸ --, --(CH₂)₂ NR⁸ CH₂ --, (CH₂)₂ NR⁸ (CH₂)₂ --, --(CH₂)₂S--, --(CH₂)₂ SCH₂ -- or --(CH₂)₂ S(CH₂)₂ --, and such groups may beunsubstituted or may have at least one substituent selected from thegroup consisting of substituents (b), defined above and exemplifiedbelow. Including such PG,17 substituted groups, the most preferredgroups which may be represented by R³ or R⁴ +R² are the group of formula--CH₂ --, --(CH₂)₂ --, --(CH₂)₃ --, --(CH₂)₄ --, --(CH₂)₂ OCH₂ --,--(CH₂)₂ SCH₂ --, --(CH₂)₂ NMeCH₂ --, --(CH₂)₂ NAcCH₂ --, --(CH₂)₂ NHCH₂--, --(CH₂)₂ NHCO--, --(CH₂)₂ NMeCO--, --CH₂ --CO--NH--CO--, --CH₂--CHMe--NH--CH₂ --, --CH₂ --CHMe--CH₂ --, --(CH₂)₂ --CHOH-- and --(CH₂)₂--CHF-- (in which Me represents the methyl group and Ac represents theacetyl group).

Where R⁶ together with R⁷ represents an alkylene group which may containan oxygen or sulfur atom or a group of formula ##STR13## (in which R⁸represents a hydrogen atom, an alkyl group or an alkanoyl group), itcontains from 1 to 6 carbon atoms in the chain and may, for example, bea group of formula --CH₂ --, --(CH₂)₂ --, --(CH₂)₃ --, --(CH₂)₄ --,--(CH₂)₅ --, --(CH₂)₆ --, --(CH₂)₂ O--, --(CH₂)₂ OCH₂ --, --CH₂ OCH₂ --,--(CH₂)₂ O(CH₂)₂ --, --(CH₂)₃ O(CH₂)₂ --, --(CH₂)₃ O(CH₂)₃ --, --CH₂ NR⁸--, --(CH₂)₂ NR⁸ --, --CH₂ NR⁸ CH₂ --, --(CH₂)₂ NR⁸ CH₂ --, (CH₂)₂ NR⁸(CH₂)₂ --, --CH₂ S--, --(CH₂)₂ S--, --CH.sub. 2 SCH₂ --, --(CH₂)₂ SCH₂-- or --(CH₂)₂ S(CH₂)₂ --, and is more preferably a group of formula--(CH₂)₂ --, --(CH₂)₃ --, --(CH₂)₄ --, --(CH₂)₅ --, --(CH₂)₂ OCH₂ --,--(CH₂)₂ O(CH₂)₂ --, --(CH₂)₂ NR⁸ CH₂ --, --(CH₂)₂ NR⁸ (CH₂)₂ --,--(CH₂)₂ SCH₂ -- or --(CH₂)₂ S(CH₂)₂, and such groups may beunsubstituted or may have at least one substituent selected from thegroup consisting of substituents (b), defined above and exemplifiedbelow. Including such substituted groups, the most preferred groupswhich may be represented by R⁶ and R⁷ together are groups of formula--(CH₂)₂ --, --(CH₂)₃ --, --(CH₂)₄ --, --(CH₂)₅ --, --(CH₂)₂ O(CH₂)₂ --,--(CH₂)₂ S(CH₂)₂, --(CH₂)₂ NHCH₂ --, --(CH₂)₂ NMeCH₂ --, --(CH₂)₂ NAcCH₂--, --CH₂ --CHOH--(CH₂)₂ --, --CH₂ --CHMe--(CH₂)₂ --, --CH₂--CHF--(CH₂)₂ --, --CO--(CH₂)₃ --, --CH(NH₂ CO)--(CH₂)₃ --, --CH₂--CH(MeO)--(CH₂)₂ --, --CH₂ --CO--(CH₂)₂ -- and --CH₂ --CH(CN)--(CH₂)₂-- groups.

Specific examples of atoms and groups which are included withinsubstituents (a) include:

hydroxy groups, cyano groups, carbamoyloxy groups, azido groups, carboxygroups, nitro groups and oxo groups;

halogen atoms, such as the chlorine, fluorine, bromine and iodine atoms,especially the chlorine and fluorine atoms;

C₁ -C₆ alkoxy groups, C₁ -C₆ alkanoyl groups, C₁ -C₆ alkanoyloxy groups,C₁ -C₆ alkanoylamino groups and C₂ -C₇ alkoxycarbonyl groups, asexemplified above;

groups of formula --NR¹⁰ R¹¹ and --CONR¹² R¹³, i.e. amino and carbamoylgroups and alkyl-substituted and alkanoyl-substituted derivativesthereof, such as the amino, methylamino, ethylamino, propylamino,isopropylamino, butylamino, isobutylamino, sec-butylamino, t-butylamino,dimethylamino, diethylamino, dipropylamino, diisopropylamino,dibutylamino, carbamoyl, methylcarbamoyl, ethylcarbamoyl,propylcarbamoyol, isopropylcarbamoyl, butylcarbamoyl, isobutylcarbamoyl,sec-butylcarbamoyl, t-butylcarbamoyl, dimethylcarbamoyl,diethylcarbamoyl, dipropylcarbamoyl, diisopropylcarbamoyl,dibutylcarbamoyl, formamido, acetamido, propionamido, butyramido,isobutyramido, valerylamino, isovalerylamino, pivaloylamino,hexanoylamino formylcarbamoyl, acetylcarbamoyl, propionylcarbamoyl,butyrylcarbamoyl, isobutyrylcarbamoyl, valerylamino, isovalerylamino,pivaloylcarbamoyl and hexanoylcarbamoyl groups;

groups of formula SO₂ NR¹⁴ R¹⁵ and --S(O)_(k) R¹⁶, i.e. sulfamoyl, thio,sulfinyl and sulfonyl groups, for example the methylsulfamoyl,ethylsulfamoyl, propylsulfamoyl, isopropylsulfamoyl, butylsulfamoyl,isobutylsulfamoyl, sec-butylsulfamoyl, t-butylsulfamoyl,dimethylsulfamoyl, diethylsulfamoyl, dipropylsulfamoyl,diisopropylsulfamoyl, dibutylsulfamoyl, and the thio, sulfinyl andsulfonyl groups exemplified for R² where R² represents a group offormula --S(O)_(j) R⁹ ;

groups of formula --NHSO₂ R¹⁷, --N═CR¹⁸ NR¹⁹ R²⁰, --N═CR²¹ CR²² ═NR²³and --C(═NH)NR²⁴ R²⁵, in which R¹⁷ to R²⁵ are as defined and exemplifiedabove.

Specific examples of atoms and groups which are included withinsubstituents (b) include:

hydroxy groups, cyano groups, carbamoyl groups, and oxo groups;

halogen atoms, C₁ -C₆ alkoxy groups and C₁ -C₆ alkyl groups, asexemplified above.

Where R², R³, R⁴, R⁶ or R⁷ represents an alkyl group having at least onesubstituent selected from the group consisting of substituents (a),these substituents are defined and exemplified above. Specific examplesof such substituted groups include the fluoromethyl, difluoromethyl,trifluoromethyl, 2-fluoroethyl, 2,2,2-trifluoroethyl, 3-fluoropropyl,2--chloroethyl, 5-fluoropentyl, 6-chlorohexyl, carbamoylmethyl,methylcarbamoylmethyl, N,N-dimethylcarbamoylmethyl, 2-carbamoylethyl,3-carbamoylpropyl, carbamoyloxymethyl, 2-carbamoyloxyethyl, cyanomethyl,2-cyanoethyl, 3-cyanopropyl, carboxymethyl, 2-carboxyethyl,4-carboxybutyl, methoxycarbonylmethyl, 2-methoxycarbonylethyl,ethoxycarbonylmethyl, 2-ethoxycarbonylethyl, 3-methoxycarbonylpropyl,3-ethoxycarbonylpropyl, hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl,4-hydroxybutyl, 5-hydroxypentyl, 6-hydroxyhexyl, methoxymethyl,2-methoxyethyl, ethoxymethyl, 4-methoxybutyl, 2-pentoxyethyl,methylthiomethyl, 2-methylthioethyl, ethylthiomethyl, 4-methylthiobutyl,3-butylthiopropyl, methylsulfinylmethyl, methylsulfonylmethyl,acetylmethyl, 2-acetylethyl, propionylmethyl, 2-propionylethyl,3-propionylpropyl, 4-propionylbutyl, N¹, N¹ -dimethylamidinomethyl,acetamidomethyl, sulfamoylmethyl, 2-(1-iminoethylamino)ethyl,nitromethyl, 2-(1-aminoethylideneamino)ethyl,2-[N-(1-iminoethyl)-N-methylamino]ethyl, dimethylaminomethyl,methylsulfonylaminomethyl, amidinomethyl,(N-iminomethyl-N-methylamino)methyl, (1-aminoethylideneamino)methyl and[N-(1-iminoethyl)-N-methylamino]methyl groups.

R⁵ represents a hydrogen atom or a protecting group, which is capable ofremoval under chemically moderate conditions such as by means of achemical reducing reagent or by catalytic reduction, or which is capableof removal by means of biological reactions, e.g. in vivo, to produce acarboxy group. There is no limitation upon the nature of such aprotecting group, provided that, where the resulting compound is to beused for therapeutic purposes, it is pharmaceutically acceptable, which,as is well-known in the art, means that the compound does not havereduced activity (or unacceptably reduced activity) or increasedtoxicity (or unacceptably increased toxicity) compared with thecorresponding compound of formula (I) where R⁵ represents a hydrogenatom. Where, however, the compound is to be used for non-therapeuticpurposes, e.g. as an intermediate in the preparation of other compounds,even this limitation does not apply, and the protecting group may bechosen having regard simply to process criteria. Examples of groupswhich may be represented by R⁵ include:

C₁ -C₂₀ alkyl groups, more preferably C₁ -C₆ alkyl groups, such as thoseexemplified in relation to R² etc. and higher alkyl groups as are wellknown in the art, such as the heptyl, octyl, nonyl and decyl groups, butmost preferably the methyl, ethyl and t-butyl groups;

C₃ -C₇ cycloalkyl groups, for example where the cycloalkyl group is anyone of those C₃ -C₆ cycloalkyl groups described herein in relation to R⁶and R⁷ or the cycloheptyl group;

aralkyl groups, as defined and exemplified above in relation to R³ andR⁴ but in which the aromatic group is C₆ -C₁₄, which may be substitutedor unsubstituted, and, if substituted may have at least one substituentselected from the group consisting of substituents (c), defined aboveand exemplified below; examples of such aralkyl groups include thebenzyl, phenethyl, 1-phenylethyl, 3-phenylpropyl, 2-phenylpropyl,1-naphthylmethyl, 2-naphthylmethyl, 2-(1-naphthyl)ethyl,2-(2-naphthyl)ethyl, benzhydryl (i.e. diphenylmethyl), triphenylmethyl,bis(o-nitrophenyl)methyl, 9-anthrylmethyl, 2,4,6-trimethylbenzyl,4-bromobenzyl, 2-nitrobenzyl, 4-nitrobenzyl, 2-nitrobenzyl,4-methoxybenzyl and piperonyl groups;

alkenyl groups such as those defined and exemplified above in relationto R³ and R⁴, but which may be substituted or unsubstituted and, ifsubstituted have at least one substituent selected from the groupconsisting of substituents (a) defined above; examples of theunsubstituted groups are given above in relation to R³ and R⁴, andpreferred groups include the allyl, 2-chloroallyl and 2-methylallylgroups;

halogenated C₁ -C₆, preferably C₁ -C₄, alkyl groups in which the alkylpart is as defined and exemplified in relation to the alkyl groups whichmay be represented by R² etc, and the halogen atom is chlorine,fluorine, bromine or iodine, such as the 2,2,2-trichloroethyl,2-haloethyl (e.g. 2-chloroethyl, 2-fluoroethyl, 2-bromoethyl or2-iodoethyl), 2,2-dibromoethyl and 2,2,2-tribromoethyl group;

substituted silylalkyl groups, in which the alkyl part is as defined andexemplified in relation to the alkyl groups which may be represented byR² etc, and the silyl group has up to 3 substituents selected from thegroup consisting of C₁ -C₆ alkyl groups and phenyl groups which areunsubstituted or have at least one substituent selected from the groupconsisting of substituents (a) defined and exemplified above, forexample a 2-trimethylsilylethyl group;

phenyl groups, in which the phenyl group is unsubstituted orsubstituted, preferably with at least one C₁ -C₄ alkyl or acylaminogroup, for example the phenyl, tolyl and benzamidophenyl groups;

phenacyl groups, which may be unsubstituted or have at least onesubstituent selected from the group consisting of substituents (a)defined and exemplified above, for example the phenacyl group itself orthe p-bromophenacyl group;

cyclic and acyclic terpenyl groups, for example the geranyl, neryl,linalyl, phytyl, menthyl (especially m- and p- menthyl), thujyl, caryl,pinanyl, bornyl, notcaryl, norpinanyl, norbornyl, menthenyl, camphenyland norbornenyl groups;

alkoxymethyl groups, in which the alkoxy part is C₁ -C₆, preferably C₁-C₄, and may itself be substituted by a single unsubstituted alkoxygroup, such as the methoxymethyl, ethoxymethyl, propoxymethyl,isopropoxymethyl, butoxymethyl and methoxyethoxymethyl groups;

aliphatic acyloxymethyl groups, in which the acyl group is preferably analkanoyl group and is more preferably a C₂ -C₆ alkanoyl group, such asthe acetoxymethyl, propionyloxymethyl, butyryloxymethyl,isobutyryloxymethyl and pivaloyloxymethyl groups;

higher aliphatic acyloxyalkyl groups in which the acyl group ispreferably an alkanoyl group and is more preferably a C₂ -C₆ alkanoylgroup, and the alkyl part is C₂ -C₆, and preferably C₂ -C₄, such as the1-pivaloyloxyethyl, 1-acetoxyethyl, 1-isobutyryloxyethyl,1-pivaloyloxypropyl, 2-methyl-1-pivaloyloxypropyl, 2-pivaloyloxypropyl,1-isobutyryloxyethyl, 1-isobutyryloxypropyl, 1-acetoxypropyl,1-acetoxy-2-methylpropyl, 1-propionyloxyethyl, 1-propionyloxypropyl,2-acetoxypropyl and 1-butyryloxyethyl groups;

cycloalkyl-substituted aliphatic acyloxyalkyl groups, in which the acylgroup is preferably an alkanoyl group and is more preferably a C₂ -C₆alkanoyl group, the cycloalkyl substituent is C₃ -C₇, and the alkyl partis a C₁ -C₆ alkyl group, preferably a C₁ -C₄ alkyl group, such as the(cyclohexylacetoxy)methyl, 1-(cyclohexylacetoxy)ethyl,1-(cyclohexylacetoxy)propyl, 2-methyl-1-(cyclohexylacetoxy)propyl,(cyclopentylacetoxy)methyl, 1-(cyclopentylacetoxy)ethyl,1-(cyclopentylacetoxy)propyl and 2-methyl-1-(cyclopentylacetoxy)propyl,groups;

alkoxycarbonyloxyalkyl groups, especially 1-(alkoxycarbonyloxy)ethylgroups, in which the alkoxy part is C₁ -C₁₀, preferably C₁ -C₆, and morepreferably C₁ -C₄, and the alkyl part is C₁ -C₆, preferably C₁ -C₄, suchas the 1-methoxycarbonyloxyethyl, 1-ethoxycarbonyloxyethyl,1-propoxycarbonyloxyethyl, 1-isopropoxycarbonyloxyethyl,1-butoxycarbonyloxyethyl, 1-isobutoxycarbonyloxyethyl,1-sec-butoxycarbonyloxyethyl, 1-t-butoxycarbonyloxyethyl,1-(1-ethylpropxycarbonyloxy)ethyl and1-(1,1-dipropylbutoxycarbonyloxy)ethyl groups, and otheralkoxycarbonylalkyl groups, in which both the alkoxy and alkyl groupsare C₁ -C₆, preferably C₁ -C₄, such as the2-methyl-1-(isopropoxycarbonyloxy)propyl,2-(isopropoxycarbonyloxy)propyl, isopropoxycarbonyloxymethyl,t-butoxycarbonyloxymethyl, methoxycarbonyloxymethyl andethoxycarbonyloxymethyl groups; cycloalkylcarbonyloxyalkyl andcycloalkyloxycarbonyloxyalkyl groups, in which the cycloalkyl group isC₃ -C₁₀, preferably C₃ -C₇, is mono-or poly- cyclic and is optionallysubstituted by at least one (and preferably only one) C₁ -C₄ alkyl group(e.g. selected from those alkyl groups exemplified above) and the alkylgroup is a C₁ -C₆, more preferably C₁ -C₄, alkyl group (e.g. selectedfrom those alkyl groups exemplified above) and is most preferablymethyl, ethyl or propyl, for example the1-methylcyclohexylcarbonyloxymethyl,1-methylcyclohexyloxycarbonyloxymethyl, cyclopentyloxycarbonyloxymethyl,cyclopentylcarbonyloxymethyl, 1-cyclohexyloxycarbonyloxyethyl,1-cyclohexylcarbonyloxyethyl, 1-cyclopentyloxycarbonyloxyethyl,1-cyclopentylcarbonyloxyethyl, 1-cycloheptyloxycarbonyloxyethyl,1-cycloheptylcarbonyloxyethyl, 1-methylcyclopentylcarbonyloxymethyl,1-methylcyclopentyloxycarbonyloxymethyl,2-methyl-1-(1-methylcyclohexylcarbonyloxy)propyl,1-(1-methylcyclohexylcarbonyloxy)propyl,2-(1-methylcyclohexylcarbonyloxy)propyl,1-(cyclohexylcarbonyloxy)propyl, 2-(cyclohexylcarbonyloxy)propyl,2-methyl-1-(1-methylcyclopentylcarbonyloxy)propyl,1-(1-methylcyclopentylcarbonyloxy)propyl,2-(1-methylcyclopentylcarbonyloxy)propyl,1-(cyclopentylcarbonyloxy)propyl, 2-(cyclopentylcarbonyloxy)propyl,1-(1-methylcyclopentylcarbonyloxy)ethyl,1-(1-methylcyclopentylcarbonyloxy)propyl, adamantyloxycarbonyloxymethyl,adamantylcarbonyloxymethyl, 1-adamantyloxycarbonoyloxyethyl and1-adamantylcarbonyloxyethyl groups;

cycloalkylalkoxycarbonyloxyalkyl groups in which the alkoxy group has asingle cycloalkyl substituent, the cycloalkyl substituent being C₃ -C₁₀,preferably C₃ -C₇, and mono- or poly- cyclic, for example thecyclopropylmethoxycarbonyloxymethyl, cyclobutylmethoxycarbonyloxymethyl,cyclopentylmethoxycarbonyloxymethyl, cyclohexylmethoxycarbonyloxymethyl,1-(cyclopropylmethoxycarbonyloxy)ethyl,1-(cyclobutylmethoxycarbonyloxy)ethyl,1-(cyclopentylmethoxycarbonyloxy)ethyl and1-(cyclohexylmethoxycarbonyloxy)ethyl groups;

terpenylcarbonyloxyalkyl and terpenyloxycarbonyloxyalkyl groups, inwhich the terpenyl group is as exemplified above in relation to theterpenyl groups which may be represented by R⁵, and is preferably acyclic terpenyl group, for example the 1-(menthyloxycarbonyloxy)ethyl,1-(menthylcarbonyloxy)ethyl, menthyloxycarbonyloxymethyl,menthylcarbonyloxymethyl, 1-(3-pinanyloxycarbonyloxy)ethyl,1-(3-pinanylcarbonyloxy)ethyl, 3-pinanyloxycarbonyloxymethyl and3-pinanylcarbonyloxymethyl groups;

5-alkyl or 5-phenyl [which may be substituted by at least onesubstituent selected from the group consisting of substituents (c)](2-oxo-1,3-dioxolen-4-yl)alkyl groups in which each alkyl group (whichmay be the same or different) is C₁ -C₆, preferably C₁ -C₄, for examplethe (5-methyl-2-oxo-1,3-dioxolen-4-yl)methyl,(5-phenyl-2-oxo-1,3-dioxolen-4-yl)methyl,(5-isopropyl-2-oxo-1,3-dioxolen-4-yl)methyl,(5-t-butyl-2-oxo-1,3-dioxolen-4-yl)methyl and1-(5-methyl-2-oxo-1,3-dioxolen-4-yl)ethyl groups; and

other groups, especially groups which are easily removed in vivo such asthe phthalidyl, indanyl and2-oxo-4,5,6,7-tetrahydro-1,3-benzodioxolen-4-yl groups.

Of the above groups, we especially prefer those groups which can beremoved easily in vivo, and most preferably the aliphatic acyloxymethylgroups, higher aliphatic acyloxyalkyl groups, cycloalkyl-aliphaticacyloxyalkyl groups, alkoxycarbonyloxyalkyl groups,cycloalkylcarbonyloxyalkyl groups, and cycloalkylalkoxycarbonyloxyalkylgroups.

Where substituents (c) are C₁ -C₄ alkyl groups, C₁ -C₄ haloalkyl groups,halogen atoms, cyano groups and nitro groups, these may be asexemplified elsewhere above. Where substituent (c) is an alkylenedioxygroup, this has from 1 to 3 carbon atoms and is preferably attached to 2adjacent positions of the benzyl group which it substitutes. Examplesinclude the methylenedioxy, dimethylenedioxy and trimethylenedioxygroups, of which the methylenedioxy group is preferred.

The compounds of the present invention can contain a basic group andcan, therefore, form acid addition salts. Also, where R⁵ represents ahydrogen atom, a cation or a protecting group and R^(a) represents saidgroup (II), an anion is required to balance the positive charge on thenitrogen atom in the group (II). This anion may be provided by an acid,as exemplified below. The nature of such salts and such acids is notcritical to the invention, provided that, where the compound is intendedfor use therapeutically, the salt is pharmaceutically acceptable, which,as is well known, means that it does not have a lower (or significantlylower) activity or a higher (or significantly higher) toxicity than thefree base. However, where the compound is intended for other uses, e.g.as an intermediate in the preparation of other compounds, even thislimitation does not apply.

Examples of acids which can form such salts or can provide the balancinganion include: inorganic acids, such as hydrochloric acid, hydrobromicacid, hydroiodic acid, phosphoric acid, sulfuric acid or nitric acid;organic sulfonic acids, such as methanesulfonic acid, ethanesulfonicacid, benzenesulfonic acid or p-toluenesulfonic acid; and organiccarboxylic acids, such as oxalic acid, tartaric acid, citric acid,maleic acid, succinic acid, acetic acid, benzoic acid, mandelic acid,ascorbic acid, lactic acid, gluconic acid and malic acid.

Examples of cations which may be represented M in the compounds of thepresent invention include: metal atoms, especially alkali metal atoms,such as the sodium and potassium atoms, and alkaline earth metal atoms,such as the calcium atom; the ammonium group; and cations derived from atrialkylamine, such as triethylamine, or from another organic base, suchas procaine, dibenzylamine or phenethylamine.

Where the compound of the invention is an ester, i.e. R⁵ represents aprotecting group, we prefer those in which:

R⁵ represents: a C₁ -C₂₀ alkyl group, more preferably a C₁ -C₆ alkylgroup; a C₃ -C₇ cycloalkyl group; an aralkyl group in which the alkylpart is C₁ -C₃ and the aromatic group is C₆ -C₁₄ and is unsubstituted orhas at least one substituent selected from the group consisting ofsubstituents (c), defined above; a C₂ -C₆ alkenyl group which isunsubstituted or has at least one substituent selected from the groupconsisting of substituents (a) defined above; a halogenated C₁ -C₆,preferably C₁ -C₄, alkyl group; a substituted silylalkyl group in whicheach alkyl part is C₁ -C₆ and the silyl group has up to 3 substituentsselected from the group consisting of C₁ -C₆ alkyl groups and phenylgroups which are unsubstituted or have at least one substituent selectedfrom the group consisting of substituents (a) defined above; a phenylgroup which is unsubstituted or has at least one C₁ -C₄ alkyl oracylamino substituent; a phenacyl group which is unsubstituted or has atleast one substituent selected from the group consisting of substituents(a) defined above; a cyclic or acyclic terpenyl group; and alkoxymethylgroup, in which the alkoxy part is C₁ -C₆, preferably C₁ -C₄, which isunsubstituted or is itself substituted by a single unsubstituted alkoxygroup; an aliphatic acyloxymethyl group, in which the acyl group ispreferably an alkanoyl group and is more preferably a C₂ -C₆ alkanoylgroup; a higher aliphatic acyloxyalkyl group in which the acyl group ispreferably an alkanoyl group and is more preferably a C₂ -C₆ alkanoylgroup, and the alkyl part is C₂ -C₆, and preferably C₂ -C₄ ; acycloalkyl-substituted aliphatic acyloxyalkyl group, in which the acylgroup is preferably an alkanoyl group and is more preferably a C₂ -C₆alkanoyl group, the cycloalkyl substituent is C₃ -C₇, and the alkyl partis a C₁ -C₆ alkyl group, preferably a C₁ -C₄ alkyl group; analkoxycarbonyloxyalkyl group, especially a 1-(alkoxycarbonyloxy)ethylgroup, in which the alkoxy part is C₁ -C₁₀, preferably C₁ -C₆, and morepreferably C₁ -C₄, and the alkyl part is C₁ -C₆, preferably C₁ -C₄ ; acycloalkylcarbonyloxyalkyl or cycloalkyloxycarbonyloxyalkyl group, inwhich the cycloalkyl group is C₃ -C₁₀, preferably C₃ -C₇, is mono- orpoly- cyclic and is optionally substituted by at least one C₁ -C₄ alkylgroup, and the alkyl group is a C₁ -C₆, more preferably C₁ -C₄, alkylgroup; a cycloalkylalkoxycarbonyloxyalkyl group in which the alkoxygroup has a single cycloalkyl substituent, the cycloalkyl substituentbeing C₃ -C₁₀, preferably C₃ -C₇, and mono- or poly- cyclic; aterpenylcarbonyloxyalkyl or terpenyloxycarbonyloxyalkyl group; a5-alkyl- or 5-phenyl- substituted (2-oxo-1,3-dioxolen-4-yl)alkyl groupin which each alkyl group is C₁ -C₆, preferably C₁ -C₄, and in which thephenyl group is unsubstituted or has at least one substituent selectedfrom the group consisting of substituents (c); a phthalidyl group; anindanyl group; or a 2-oxo-4,5,6,7-tetrahydro-1,3-benzodioxolen-4-ylgroup.

Of all of the compounds of the present invention, we prefer those inwhich R^(a) represents said group of formula (II). Of the compoundswhere R^(a) represents said group of formula (II), the following arepreferred:

(A) those compounds of formula (I), in which:

R^(a) represents said group of formula (II), in which:

one of the symbols R' represents a bond to the remainder of the compoundof formula (I), one more of the symbols R' is R² and the others of thesymbols R' all represent hydrogen atoms;

R¹ represents a hydrogen atom or a methyl group;

R² represents a hydrogen atom, a C₁ -C₄ alkyl group, a C₁ -C₄ alkylgroup having at least one substituent selected from the group consistingof substituents (a'), a halogen atom, a hydroxy group, a C₁ -C₄ alkoxygroup, an amino group, a C₁ -C₆ alkanoylamino group, a C₁ -C₆alkanoyloxy group, a C₁ -C₆ alkanoyl group, a carboxy group, a C₂ -C₅alkoxycarbonyl group, a cyano group, a group of formula --S(O)_(j) R⁹

wherein j is zero or an integer 1 or 2 and R⁹ represents a C₁ -C₄ alkylgroup;

or a group of formula --CONR⁶ R⁷

wherein R⁶ and R⁷ are independently selected from the group consistingof hydrogen atoms, C₁ -C₄ alkyl groups, C₃ -C₆ cycloalkyl groups, C₂ -C₄alkenyl groups, C₃ -C₄ alkynyl groups and C₁ -C₄ alkyl groups having atleast one substituent selected from the group consisting of substituents(a'), or R⁶ and R⁷ together represent a C₂ -C₄ alkylene group or a C₂-C₄ alkylene group whose carbon chain is interrupted by an oxygen orsulfur atom or by a group of formula ##STR14## wherein R⁸ represents ahydrogen atom, a C₁ -C₄ alkyl group of a C₁ -C₆ alkanoyl group,

or R⁶ and R⁷ together represent said alkylene group having at least onesubstituent selected from the group consisting of substituents (b),defined above;

R³ and R⁴ are independently selected from the group consisting of C₁ -C₄alkyl groups, C₃ -C₄ alkenyl groups, C₃ -C₄ alkynyl groups, benzylgroups, cycloalkylalkyl groups where the alkyl part is C₁ -C₃ alkyl andthe cycloalkyl part is C₃ -C₆, and C₁ -C₄ alkyl groups having at leastone substituent selected from the group consisting of substituents (a'),or one of R³ and R⁴, together with R², represents a C₂ -C₄ alkylenegroup whose carbon chain is interupted by an oxygen or sulfur atom or bya group of formula ##STR15## wherein R⁸ is as defined above, or one ofR³ and R⁴, together with R², represents said alkylene group having atleast one substituent selected from the group consisting of substituents(b), defined below; and

--COOR⁵ represents a carboxy group, a group of formula --COO⁻ or a groupof formula --COOM_(x), where M is a cation and x is the reciprocal ofthe valence of the cation M, or R⁵ is as defined in (A) above, and,where --COOR⁵ represents a carboxy group, a group of formula --COOM_(x)or a protected carboxy group, the compound of formula (I) also containsan anion;

l is zero or 1 and (m+n) is an integer from 2 to 6;

Y represents a single bond, an oxygen atom, a sulfur atom or a group offormula ##STR16## wherein R⁸ is as defined above, substituents (a')

hydroxy group, cyano groups, carbamoyloxy groups, carboxy groups, nitrogroups, halogen atoms, C₁ -C₃ alkoxy groups, C₁ -C₆ alkanoyl groups, C₁-C₆ alkanoyloxy groups, C₁ -C₆ alkanoylamino groups, C₂ -C₅alkoxycarbonyl groups, groups of formula --NR¹⁰ R¹¹ and --CONR¹² R¹³

in which R¹⁰, R¹¹, R¹² and R¹³ are independently selected from the groupconsisting of hydrogen atoms, C₁ -C₄ alkyl groups and C₁ -C₆ alkanoylgroups,

groups of formula --SO₂ NR¹⁴ R¹⁵ and --S(O)_(k) R¹⁶

wherein R¹⁴, R¹⁵ and R¹⁶ are independently selected from the groupconsisting of C₁ -C₄ alkyl groups and k is zero or an integer 1 or 2,and

groups of formula --NHSO₂ R¹⁷, --N═CR¹⁸ NR¹⁹ R²⁰, --N═CR²¹ CR²² ═NR²³and --C(═NH)NR²⁴ R²⁵

wherein R¹⁷ to R²⁵ are independently selected from the group consistingof hydrogen atoms and C₁ -C₄ alkyl groups;

and pharmaceutically acceptable salts and esters thereof.

The more preferred of these compounds are those in which:

(B) R¹ represents a hydrogen atom or a methyl group; l is zero or aninteger 1 or 2; (m+n) is an integer 2, 3, 4, 5 or 6; Y represents asingle bond, an oxygen atom, a sulfur atom or a group of formula##STR17## (wherein R⁸ represents a hydrogen atom, a methyl group, anethyl group, a formyl group or an acetyl group); R² represents ahydrogen atom, a fluorine atom, a hydroxy group, a methoxy group, anethoxy group, an amino group, an acetamido group, an acetoxy group, aformyl group, an acetyl group, a carboxy group, a methoxycarbonyl group,an ethoxycarbonyl group, a cyano group, a group of formula --CONR⁶ R⁷,wherein:

R⁶ and R⁷ are independently selected from the group consisting ofhydrogen atoms, C₁ -C₃ alkyl groups, allyl groups, propargyl groups andalkyl groups having at least one substituent selected from the groupconsisting of substituents (a), defined above, or R⁶ and R⁷ togetherrepresent a group of formula --(CH₂)₃ --, --(CH₂)₄ --, --(CH₂)₅ --,--(CH₂)₂ OCH₂ --, --(CH₂)₂ O(OH₂)₂ --, --(CH₂)₂ NR⁸ (CH₂)₂ --, wherein:

R⁸ represents a hydrogen atom, or a methyl, formyl or acetyl group,

--(CH₂)₂ SCH₂ -- or --(CH₂)₂ S(CH₂)₂ --,

a group of formula --S(O)_(j) R⁹, wherein:

j is zero or an integer 1 or 2 and R⁹ represents a methyl, ethyl orpropyl group.

a methyl group, an ethyl group or a propyl group; the substituent on thealkyl group in R³ and R⁴ is a hydroxy, cyano, carbamoyl, carboxy ornitro group, or a fluorine or chlorine atom, or a methoxy, ethoxy,acetyl, formyl, acetoxy, acetylamino, formylamino, methoxycarbonyl orethoxycarbonyl group, or a group of formula --NR¹⁰ R¹¹, wherein:

R¹⁰ and R¹¹ are independently selected from the group consisting ofhydrogen atoms, methyl groups and ethyl groups,

a group of formula --CONR¹² R¹³, wherein:

R¹² and R¹³ are independently selected from the group consisting ofhydrogen atoms, methyl groups and ethyl groups,

a group of formula --SO₂ NR¹⁴ R¹⁵, wherein:

R¹⁴ and R¹⁵ are independently selected from the group consisting ofhydrogen atoms, methyl groups and ethyl groups,

a group of formula --S(O)_(t) R¹⁶, wherein:

t is zero or an integer 1 or 2 and R¹⁶ represents a methyl group,

a group of formula --NHSO₂ R¹⁷, wherein:

R¹⁷ represents a methyl or ethyl groups,

a group of formula --N═CR¹⁸ NR¹⁹ R²⁰ or --NR²¹ CR²² ═NR²³, wherein:

R¹⁸ to R²³ are independently selected from the group consisting ofhydrogen atoms, methyl groups and ethyl groups,

or a group of formula --C(═NH)NR²⁴ R²⁵, wherein:

R²⁴ and R²⁵ are independently selected from the group consisting ofhydrogen atoms, methyl groups and ethyl groups;

R³ and R⁴ are independently selected from the group consisting ofmethyl, ethyl, propyl, allyl, propargyl, benzyl and cyclopropylmethylgroups, or together with R² represent a group of formula --(CH₂)₂ --,--(CH₂)₃ --, --(CH₂)₄ --, --(CH₂)₅ --, --(CH₂)--O--, --(CH₂)₂ --OCH₂ --,--(CH₂)--O--(CH₂)₂ --, --(CH₂)--NR⁸ --, --(CH₂)₂ --NR⁸ CH₂ --, --(CH₂)₂--NR⁸ --(CH₂)₂ --, wherein:

R⁸ represents a hydrogen atom or a methyl, ethyl, formyl or acetylgroup, --(CH₂)--S--, --(CH₂)₂ --SCH₂ -- or --(CH₂)₂ --S--(CH₂)₂ --; and

where R⁶ together with R⁷ represents an alkylene group which issubstituted or either R³ or R⁴ together with R² represents an alkylenegroup which is substituted, the substituent is a methyl or ethyl group,a fluorine atom, a hydroxy group or an oxo group.

Of the compounds of the present invention where R^(a) represents a groupof formula (III), we prefer:

(C) those in which:

p is 1, and particularly where the group of formula (III) is apyrrolidin-2-one-4-yl group, which has the group R^(2a) at its nitrogenatom; and

R^(2a) is a hydrogen atom, a C₁ -C₄ alkyl group, more preferably amethyl, ethyl, propyl or butyl group, or a C₁ -C₄ alkanoyl group, morepreferably a formyl, acetyl, propionyl or butyryl group, and is mostpreferably a hydrogen atom, i.e. the pyrrolidin-2-one-4-yl group isunsubstituted.

The compounds of formula (I) can exist in the form of various isomersbecause of the presence of asymmetric carbon atoms. Both the individualisomers and mixtures of two or more isomers are included in the presentinvention. Such mixtures may be prepared as a result of the synthesisreactions or by mixing. Where an individual isomer is required, this maybe prepared by a stereo-specific synthesis route or it may be preparedby separating a mixture of isomers, using separation techniques wellknown in the art. We particularly prefer those compounds in which the1-hydroxyethyl group at the 6-penem position is in the sameconfiguration as thienamycin, i.e. it is 1(R)-hydroxyethyl. Also, whenR¹ represents a hydrogen atom, the (5R, 6S) configuration is preferred,and, when R¹ represents a methyl group, the (1R, 5S, 6S) configurationis preferred.

Specific Examples of compounds of the invention are given in thefollowing formulae (I-1) to (I-9), in which the substituents are asdefined in the corresponding one of Tables 1 to 9 [i.e. Table 1 relatesto formula (I-1), Table 2 relates to formula (I-2) and so on]. In Table4, where the group represented by Z is asymmetric, the atom attached tothe nitrogen atom is shown first. In Table 6, where the grouprepresented by Z' is asymmetric, the atom attached to the nitrogen atomis shown at the end. In Table 7, where the bond to the remainder of themolecule is at the position marked *, that position is occupied by acarbon atom (one of the bonds of which is attached to the remainder ofthe molecule), and the position marked ** is occupied by a ##STR18##group; where the bond to the remainder of the molecule is at theposition marked **, that position is occupied by a ##STR19## group (oneof the bonds of which is attached to the remainder of the molecule), andthe position marked * is occupied by a ##STR20## group. In the Tables,the following abbreviations are used:

    ______________________________________                                        Ac       acetyl                                                               Ada      adamantyl                                                            All      allyl                                                                Azr      aziridinyl                                                           Azt      azetidinyl                                                           Bu       butyl                                                                 -cBu    cyclobutyl                                                            .sub.-sBu                                                                             sec-butyl                                                             .sub.-tBu                                                                             t-butyl                                                              Byr      butyryl                                                               .sub.-iByr                                                                            isobutyryl                                                           Bz       benzyl                                                               Car      carbamoyl                                                            Dix      2-oxo-1,3-dioxolen-4-yl                                              Dox      (5-methyl-2-oxo-1,3-dioxolen-4-yl)methyl                             Et       ethyl                                                                Etc      ethoxycarbonyl                                                        -cHp    cycloheptyl                                                           -cHx    cyclohexyl                                                           Me       methyl                                                               Mec      methoxycarbonyl                                                      Men      menthyl                                                              Mor      morpholino                                                           Pdox     (5-phenyl-2-oxo-1,3-dioxolen-4-yl)methyl                             Ph       phenyl                                                               Phth     phthalidyl                                                           Pip      piperidyl                                                            Piv      pivaloyl                                                             Piz      piperazinyl                                                           -cPn    cyclopentyl                                                          Pr       propyl                                                                -cPr    cyclopropyl                                                           .sub.-iPr                                                                             isopropyl                                                            Prg      propargyl (= 2-propynyl)                                             Prn      propionyl                                                            Pyrd     pyrrolidinyl                                                         Tfm      trifluoromethyl                                                      Thz      perhydro-1,4-thiazin-4-yl (= thiomorpholino)                          ##STR21##                    (I-1)                                            ##STR22##                    (I-2)                                            ##STR23##                    (I-3)                                            ##STR24##                    (I-4)                                            ##STR25##                    (I-5)                                            ##STR26##                    (I-6)                                            ##STR27##                    (I-7)                                            ##STR28##                    (I-8)                                            ##STR29##                    (I-9)                                           ______________________________________                                    

                                      TABLE 1                                     __________________________________________________________________________    Cpd.                                                                          No. R.sup.1                                                                           R.sup.2      R.sup.3       R.sup.4                                                                            l                                     __________________________________________________________________________    1-1 Me  Car          Me            Me   0                                     1-2 H   Car          Me            Me   0                                     1-3 Me  Car          2-FEt         Me   0                                     1-4 H   Car          2-FEt         Me   0                                     1-5 Me  MeCar        Me            Me   0                                     1-6 H   MeCar        Me            Me   0                                     1-7 Me  Car          All           Me   0                                     1-8 H   Car          All           Me   0                                     1-9 Me  Car          Et            Me   0                                     1-10                                                                              H   Car          Et            Me   0                                     1-11                                                                              Me  Car          CH.sub.2 Car  Me   0                                     1-12                                                                              H   Car          CH.sub.2 Car  Me   0                                     1-13                                                                              Me  Car          CH.sub.2 CN   Me   0                                     1-14                                                                              H   Car          CH.sub.2 CN   Me   0                                     1-15                                                                              Me  Car          CH.sub.2 COOH Me   0                                     1-16                                                                              H   Car          CH.sub.2 COOH Me   0                                     1-17                                                                              Me  Car          CH.sub.2 OMe  Me   0                                     1-18                                                                              H   Car          CH.sub.2 OMe  Me   0                                     1-19                                                                              Me  MeCar        2-FEt         Me   0                                     1-20                                                                              H   MeCar        2-FEt         Me   0                                     1-21                                                                              Me  MeCar        Et            Me   0                                     1-22                                                                              H   MeCar        Et            Me   0                                     1-23                                                                              Me  diMeCar      Me            Me   0                                     1-24                                                                              H   diMeCar      Me            Me   0                                     1-25                                                                              Me  diMeCar      Et            Me   0                                     1-26                                                                              H   diMeCar      Et            Me   0                                     1-27                                                                              Me  diMeCar      2-FEt         Me   0                                     1-28                                                                              H   diMeCar      2-FEt         Me   0                                     1-29                                                                              Me  diMeCar      All           Me   0                                     1-30                                                                              H   DiMeCar      All           Me   0                                     1-31                                                                              Me  Car          CH.sub.2 SMe  Me   0                                     1-32                                                                              H   Car          CH.sub.2 SMe  Me   0                                     1-33                                                                              Me  Car          Prg           Me   0                                     1-34                                                                              H   Car          Prg           Me   0                                     1-35                                                                              Me  CONH(2-FEt)  Me            Me   0                                     1-36                                                                              H   CONH(2-FEt)  Me            Me   0                                     1-37                                                                              Me  CONMe(2-FEt) Me            Me   0                                     1-38                                                                              H   CONMe(2-FEt) Me            Me   0                                     1-39                                                                              Me  CONMe(2-HOEt)                                                                              Me            Me   0                                     1-40                                                                              H   CONMe(2-HOEt)                                                                              Me            Me   0                                     1-41                                                                              Me  CONMe(3-FPr) Me            Me   0                                     1-42                                                                              H   CONMe(3-FPr) Me            Me   0                                     1-43                                                                              Me  CONMe(CHF.sub.2)                                                                           Me            Me   0                                     1-44                                                                              H   CONMe(CHF.sub.2)                                                                           Me            Me   0                                     1-45                                                                              Me  Car          CH.sub.2 Ac   Me   0                                     1-46                                                                              H   Car          CH.sub.2 Ac   Me   0                                     1-47                                                                              Me  Car          CH.sub.2 COOMe                                                                              Me   0                                     1-48                                                                              H   Car          CH.sub.2 COOMe                                                                              Me   0                                     1-49                                                                              Me  Car          2-HOEt        Me   0                                     1-50                                                                              H   Car          2-HOEt        Me   0                                     1-51                                                                              Me  H            Me            Me   0                                     1-52                                                                              H   H            Me            Me   0                                     1-53                                                                              Me  H            CH.sub.2 Car  Me   0                                     1-54                                                                              H   H            CH.sub.2 Car  Me   0                                     1-55                                                                              Me  H            2-FEt         Me   0                                     1-56                                                                              H   H            2-FEt         Me   0                                     1-57                                                                              Me  H            CH.sub.2 CN   Me   0                                     1-58                                                                              H   H            CH.sub.2 CN   Me   0                                     1-59                                                                              Me  H            CH.sub.2 Ac   Me   0                                     1-60                                                                              H   H            CH.sub.2 Ac   Me   0                                     1-61                                                                              Me  H            CH.sub.2 COOMe                                                                              Me   0                                     1-62                                                                              H   H            CH.sub.2 COOMe                                                                              Me   0                                     1-63                                                                              Me  H            CH.sub.2 COOH Me   0                                     1-64                                                                              H   H            CH.sub.2 COOH Me   0                                     1-65                                                                              Me  H            2-HOEt        Me   0                                     1-66                                                                              H   H            2-HOEt        Me   0                                     1-67                                                                              Me  H            CH.sub.2 OMe  Me   0                                     1-68                                                                              H   H            CH.sub.2 OMe  Me   0                                     1-69                                                                              Me  H            CH.sub.2 SMe  Me   0                                     1-70                                                                              H   H            CH.sub.2 SMe  Me   0                                     1-71                                                                              Me  H            CH.sub.2 SOMe Me   0                                     1-72                                                                              H   H            CH.sub.2 SOMe Me   0                                     1-73                                                                              Me  H            CH.sub.2 SO.sub.2 Me                                                                        Me   0                                     1-74                                                                              H   H            CH.sub.2 SO.sub.2 Me                                                                        Me   0                                     1-75                                                                              Me  H            All           Me   0                                     1-76                                                                              H   H            All           Me   0                                     1-77                                                                              Me  H            Prg           Me   0                                     1-78                                                                              H   H            Prg           Me   0                                     1-79                                                                              Me  H            Bz            Me   0                                     1-80                                                                              H   H            Bz            Me   0                                     1-81                                                                              Me  H            CH.sub.2 - -cPr                                                                             Me   0                                     1-82                                                                              H   H            CH.sub.2 - -cPr                                                                             Me   0                                     1-83                                                                              Me  H            CH.sub.2 - -cPn                                                                             Me   0                                     1-84                                                                              H   H            CH.sub.2 - -cPn                                                                             Me   0                                     1-85                                                                              Me  H            Et            Me   0                                     1-86                                                                              H   H            Et            Me   0                                     1-87                                                                              Me  H            CH.sub.2 diMeCar                                                                            Me   0                                     1-88                                                                              H   H            CH.sub.2 diMeCar                                                                            Me   0                                     1-89                                                                              Me  H            CH.sub.2 MeCar                                                                              Me   0                                     1-90                                                                              H   H            CH.sub.2 MeCar                                                                              Me   0                                     1-91                                                                              Me  H            Me            Me   1                                     1-92                                                                              H   H            Me            Me   1                                     1-93                                                                              Me  H            CH.sub.2 Car  Me   1                                     1-94                                                                              H   H            CH.sub.2 Car  Me   1                                     1-95                                                                              Me  H            Et            Me   1                                     1-96                                                                              H   H            Et            Me   1                                     1-97                                                                              Me  H            CH.sub.2 MeCar                                                                              Me   1                                     1-98                                                                              H   H            CH.sub.2 MeCar                                                                              Me   1                                     1-99                                                                              Me  H            CH.sub.2 diMeCar                                                                            Me   1                                     1-100                                                                             H   H            CH.sub.2 diMeCar                                                                            Me   1                                     1-101                                                                             Me  H            All           Me   1                                     1-102                                                                             H   H            All           Me   1                                     1-103                                                                             Me  H            Prg           Me   1                                     1-104                                                                             H   H            Prg           Me   1                                     1-105                                                                             Me  H            Bz            Me   1                                     1-106                                                                             H   H            Bz            Me   1                                     1-107                                                                             Me  H            CH.sub.2 CN   Me   1                                     1-108                                                                             H   H            CH.sub.2 CN   Me   1                                     1-109                                                                             Me  H            CH.sub.2 COOMe                                                                              Me   1                                     1-110                                                                             H   H            CH.sub.2 COOMe                                                                              Me   1                                     1-111                                                                             Me  H            CH.sub.2 COOH Me   1                                     1-112                                                                             H   H            CH.sub.2 COOH Me   1                                     1-113                                                                             Me  H            CH.sub.2  -cPr                                                                              Me   1                                     1-114                                                                             H   H            CH.sub.2  -cPr                                                                              Me   1                                     1-115                                                                             Me  H            CH.sub.2 Ac   Me   1                                     1-116                                                                             H   H            CH.sub.2 Ac   Me   1                                     1-117                                                                             Me  H            2-HOEt        Me   1                                     1-118                                                                             H   H            2-HOEt        Me   1                                     1-119                                                                             Me  H            CH.sub.2 OMe  Me   1                                     1-120                                                                             H   H            CH.sub.2 OMe  Me   1                                     1-121                                                                             Me  H            CH.sub.2 SMe  Me   1                                     1-122                                                                             H   H            CH.sub.2 SMe  Me   1                                     1-123                                                                             Me  H            2-(CarO)Et    Me   1                                     1-124                                                                             H   H            2-(CarO)Et    Me   1                                     1-125                                                                             Me  H            CH.sub.2 SOMe Me   1                                     1-126                                                                             H   H            CH.sub.2 SOMe Me   1                                     1-127                                                                             Me  H            CH.sub.2 SO.sub.2 Me                                                                        Me   1                                     1-128                                                                             H   H            CH.sub.2 SO.sub.2 Me                                                                        Me   1                                     1-129                                                                             Me  H            CH.sub.2 C(NH)NMe.sub.2                                                                     Me   0                                     1-130                                                                             H   H            CH.sub.2 C(NH)NMe.sub.2                                                                     Me   0                                     1-131                                                                             Me  COOMe        Me            Me   0                                     1-132                                                                             H   COOMe        Me            Me   0                                     1-133                                                                             Me  CH.sub.2 OH  Me            Me   0                                     1-134                                                                             H   CH.sub.2 OH  Me            Me   0                                     1-135                                                                             Me  CH.sub.2 F   Me            Me   0                                     1-136                                                                             H   CH.sub.2 F   Me            Me   0                                     1-137                                                                             Me  Me           Me            Me   0                                     1-138                                                                             H   Me           Me            Me   0                                     1-139                                                                             Me  OCar         Me            Me   0                                     1-140                                                                             H   OCar         Me            Me   0                                     1-141                                                                             Me  OAc          Me            Me   0                                     1-142                                                                             H   OAc          Me            Me   0                                     1-143                                                                             Me  Ac           Me            Me   0                                     1-144                                                                             H   Ac           Me            Me   0                                     1-145                                                                             Me  CN           Me            Me   0                                     1-146                                                                             H   CN           Me            Me   0                                     1-147                                                                             Me  CH.sub.2 NHAc                                                                              Me            Me   0                                     1-148                                                                             H   CH.sub.2 NHAc                                                                              Me            Me   0                                     1-149                                                                             Me  CH.sub.2 OMe Me            Me   0                                     1-150                                                                             H   CH.sub.2 OMe Me            Me   0                                     1-151                                                                             Me  CH.sub.2 SMe Me            Me   0                                     1-152                                                                             H   CH.sub.2 SMe Me            Me   0                                     1-153                                                                             Me  CH.sub.2 SOMe                                                                              Me            Me   0                                     1-154                                                                             H   CH.sub.2 SOMe                                                                              Me            Me   0                                     1-155                                                                             Me  CH.sub.2 SO.sub.2 Me                                                                       Me            Me   0                                     1-156                                                                             H   CH.sub.2 SO.sub.2 Me                                                                       Me            Me   0                                     1-157                                                                             Me  CH.sub.2 OH  Et            Me   0                                     1-158                                                                             H   CH.sub.2 OH  Et            Me   0                                     1-159                                                                             Me  CH.sub.2 OH  All           Me   0                                     1-160                                                                             H   CH.sub.2 OH  All           Me   0                                     1-161                                                                             Me  CH.sub.2 OH  2-FEt         Me   0                                     1-162                                                                             H   CH.sub.2 OH  2-FEt         Me   0                                     1-163                                                                             Me  CH.sub.2 OH  CH.sub.2 Car  Me   0                                     1-164                                                                             H   CH.sub.2 OH  CH.sub.2 Car  Me   0                                     1-165                                                                             Me  CH.sub.2 OH  CH.sub.2 CN   Me   0                                     1-166                                                                             H   CH.sub.2 OH  CH.sub.2 CN   Me   0                                     1-167                                                                             Me  H            CH.sub.2 SO.sub.2 NH.sub.2                                                                  Me   0                                     1-168                                                                             H   H            CH.sub.2 SO.sub.2 NH.sub.2                                                                  Me   0                                     1-169                                                                             Me  H            2-FEt         2-FEt                                                                              0                                     1-170                                                                             H   H            2-FEt         2-FEt                                                                              0                                     1-171                                                                             Me  H            CH.sub.2 Car  Et   0                                     1-172                                                                             H   H            CH.sub.2 Car  Et   0                                     1-173                                                                             Me  H            3-FPr         Me   0                                     1-174                                                                             H   H            3-FPr         Me   0                                     1-175                                                                             Me  H            2-(NHAc)Et    Me   0                                     1-176                                                                             H   H            2-(NHAc)Et    Me   0                                     1-177                                                                             Me  H            2-(NH.sub.2)Et                                                                              Me   0                                     1-178                                                                             H   H            2-(NH.sub.2)Et                                                                              Me   0                                     1-179                                                                             Me  H            2-(NHCMeNH)Et Me   0                                     1-180                                                                             H   H            2-(NHCMeNH)Et Me   0                                     1-181                                                                             Me  H            2-ClEt        Me   0                                     1-182                                                                             H   H            2-ClEt        Me   0                                     1-183                                                                             Me  H            2-CarEt       Me   0                                     1-184                                                                             H   H            2-CarEt       Me   0                                     1-185                                                                             Me  1-Pyrd-CO    Me            Me   0                                     1-186                                                                             H   1-Pyrd-CO    Me            Me   0                                     1-187                                                                             Me  1-Pip-CO     Me            Me   0                                     1-188                                                                             H   1-Pip-CO     Me            Me   0                                     1-189                                                                             Me  Mor-CO       Me            Me   0                                     1-190                                                                             H   Mor-CO       Me            Me   0                                     1-191                                                                             Me  Thz-CO       Me            Me   0                                     1-192                                                                             H   Thz-CO       Me            Me   0                                     1-193                                                                             Me  (2-MeOEt)Car Me            Me   0                                     1-194                                                                             H   (2-MeOEt)Car Me            Me   0                                     1-195                                                                             Me  H            3-FPr         Me   0                                     1-196                                                                             H   H            3-FPr         Me   0                                     1-197                                                                             Me  CH.sub.2 NO.sub.2                                                                          Me            Me   0                                     1-198                                                                             H   CH.sub.2 NO.sub.2                                                                          Me            Me   0                                     1-199                                                                             Me  H            Et            Et   0                                     1-200                                                                             H   H            Et            Et   0                                     1-201                                                                             Me  H            CH.sub.2 Car  Et   0                                     1-202                                                                             H   H            CH.sub.2 Car  Et   0                                     1-203                                                                             Me  CH.sub.2 Car Me            Me   0                                     1-204                                                                             H   CH.sub.2 Car Me            Me   0                                     1-205                                                                             Me  H            2-(NH.sub.2 CMeN)Et                                                                         Me   0                                     1-206                                                                             H   H            2-(NH.sub.2 CMeN)Et                                                                         Me   0                                     1-207                                                                             Me  H                                                                                           ##STR30##    Me   0                                     1-208                                                                             H   H                                                                                           ##STR31##    Me   0                                     1-209                                                                             Me  H            CH.sub.2 CF.sub.3                                                                           Me   0                                     1-210                                                                             H   H            CH.sub.2 CF.sub.3                                                                           Me   0                                     1-211                                                                             Me  1-Piz-CO     Me            Me   0                                     1-212                                                                             H   1-Piz-CO     Me            Me   0                                     1-213                                                                             Me  4-Ac-1-Piz-CO                                                                              Me            Me   0                                     1-214                                                                             H   4-Ac-1-Piz-CO                                                                              Me            Me   0                                     1-215                                                                             Me  4-Me-1-Piz-CO                                                                              Me            Me   0                                     1-216                                                                             H   4-Me-1-Piz-CO                                                                              Me            Me   0                                     1-217                                                                             Me  CHO          Me            Me   0                                     1-218                                                                             H   CHO          Me            Me   0                                     1-219                                                                             Me  Etc          Me            Me   0                                     1-220                                                                             H   Etc          Me            Me   0                                     1-221                                                                             Me  1-Azt-CO     Me            Me   0                                     1-222                                                                             H   1-Azt-CO     Me            Me   0                                     1-223                                                                             Me  1-Azr-CO     Me            Me   0                                     1-224                                                                             H   1-Azr-CO     Me            Me   0                                     1-225                                                                             Me  CH.sub.2 CN  Me            Me   0                                     1-226                                                                             H   CH.sub.2 CN  Me            Me   0                                     1-227                                                                             Me  CH.sub.2 F   Me            Me   0                                     1-228                                                                             H   CH.sub.2 F   Me            Me   0                                     1-229                                                                             Me  CH.sub.2 NMe.sub.2                                                                         Me            Me   0                                     1-230                                                                             H   CH.sub.2 NMe.sub.2                                                                         Me            Me   0                                     1-231                                                                             Me  CH.sub.2 NHSO.sub.2 Me                                                                     Me            Me   0                                     1-232                                                                             H   CH.sub.2 NHSO.sub.2 Me                                                                     Me            Me   0                                     1-233                                                                             Me  CH.sub.2 SO.sub.2 NH.sub.2                                                                 Me            Me   0                                     1-234                                                                             H   CH.sub.2 SO.sub.2 NH.sub.2                                                                 Me            Me   0                                     1-235                                                                             Me                                                                                 ##STR32##   Me            Me   0                                     1-236                                                                             H                                                                                  ##STR33##   Me            Me   0                                     1-237                                                                             Me  CH.sub.2 NCHNH.sub.2                                                                       Me            Me   0                                     1-238                                                                             H   CH.sub.2 NCHNH.sub.2                                                                       Me            Me   0                                     1-239                                                                             Me  CH.sub.2 NMeCH NH                                                                          Me            Me   0                                     1-240                                                                             H   CH.sub.2 NMeCHNH                                                                           Me            Me   0                                     1-241                                                                             Me  CH.sub.2 NCHMeNH.sub.2                                                                     Me            Me   0                                     1-242                                                                             H   CH.sub.2 NCHMeNH.sub.2                                                                     Me            Me   0                                     1-243                                                                             Me  CH.sub.2 NMeCMeNH                                                                          Me            Me   0                                     1-244                                                                             H   CH.sub.2 NMeCMeNH                                                                          Me            Me   0                                     1-245                                                                             Me  H            2-MeSEt       Me   0                                     1-246                                                                             H   H            2-MeSEt       Me   0                                     1-247                                                                             Me  H            2-MeOEt       Me   0                                     1-248                                                                             H   H            2-MeOEt       Me   0                                     1-249                                                                             Me  Car          Et            Et   0                                     1-250                                                                             H   Car          Et            Et   0                                     1-251                                                                             Me  3-HO-1-Pyrd-CO                                                                             Me            Me   0                                     1-252                                                                             H   3-HO-1-Pyrd-CO                                                                             Me            Me   0                                     1-253                                                                             Me  3-Me-1-Pyrd-CO                                                                             Me            Me   0                                     1-254                                                                             H   3-Me-1-Pyrd-CO                                                                             Me            Me   0                                     1-255                                                                             Me  2-oxo-1-Pyrd-CO                                                                            Me            Me   0                                     1-256                                                                             H   2-oxo-1-Pyrd-CO                                                                            Me            Me   0                                     1-257                                                                             Me  3-F-1-Pyrd-CO                                                                              Me            Me   0                                     1-258                                                                             H   3-F-1-Pyrd-CO                                                                              Me            Me   0                                     1-259                                                                             Me  2-Car-1-Pyrd-CO                                                                            Me            Me   0                                     1-260                                                                             H   2-Car-1-Pyrd-CO                                                                            Me            Me   0                                     1-261                                                                             Me  3-MeO-1-Pyrd-CO                                                                            Me            Me   0                                     1-262                                                                             H   3-MeO-1-Pyrd-CO                                                                            Me            Me   0                                     1-263                                                                             Me  3-oxo-1-Pyrd-CO                                                                            Me            Me   0                                     1-264                                                                             H   3-oxo-1-Pyrd-CO                                                                            Me            Me   0                                     1-265                                                                             Me  3-NC-1-Pyrd-CO                                                                             Me            Me   0                                     1-266                                                                             H   3-NC-1-Pyrd-CO                                                                             Me            Me   0                                     1-267                                                                             Me  EtCar        Me            Me   0                                     1-268                                                                             H   EtCar        Me            Me   0                                     1-269                                                                             Me  EtCar        Et            Me   0                                     1-270                                                                             H   EtCar        Et            Me   0                                     1-271                                                                             Me   .sub.-iPrCar                                                                              Me            Me   0                                     1-272                                                                             H    .sub.-iPrCar                                                                              Me            Me   0                                     1-273                                                                             Me   .sub.-iPrCar                                                                              Et            Me   0                                     1-274                                                                             H    .sub.-iPrCar                                                                              Et            Me   0                                     1-275                                                                             Me   -cPrCar     Me            Me   0                                     1-276                                                                             H    -cPrCar     Me            Me   0                                     1-277                                                                             Me   -cPrCar     Et            Me   0                                     1-278                                                                             H    -cPrCar     Et            Me   0                                     __________________________________________________________________________

                  TABLE 2                                                         ______________________________________                                        Cpd.                                                                          No.      R.sup.1  R.sup.3      R.sup.4                                                                            l                                         ______________________________________                                        2-1      Me       Me           Me   0                                         2-2      H        Me           Me   0                                         2-3      Me       --CH.sub.2 Car                                                                             Me   0                                         2-4      H        --CH.sub.2 Car                                                                             Me   0                                         2-5      Me       --CH.sub.2 CN                                                                              Me   0                                         2-6      H        --CH.sub.2 CN                                                                              Me   0                                         2-7      Me       --CH.sub.2 Ac                                                                              Me   0                                         2-8      H        --CH.sub.2 Ac                                                                              Me   0                                         2-9      Me       2-FEt        Me   0                                         2-10     H        2-FEt        Me   0                                         2-11     Me       2-HOEt       Me   0                                         2-12     H        2-HOEt       Me   0                                         2-13     Me       --CH.sub.2 --diMeCar                                                                       Me   0                                         2-14     H        --CH.sub.2 ---diMeCar                                                                      Me   0                                         2-15     Me       All          Me   0                                         2-16     H        All          Me   0                                         2-17     Me       Prg          Me   0                                         2-18     H        Prg          Me   0                                         2-19     Me       --CH.sub.2 OMe                                                                             Me   0                                         2-20     H        --CH.sub.2 OMe                                                                             Me   0                                         2-21     Me       Et           Me   0                                         2-22     H        Et           Me   0                                         2-23     Me       --CH.sub.2 --MeCar                                                                         Me   0                                         2-24     H        --CH.sub.2 --MeCar                                                                         Me   0                                         2-25     Me       2-CarOEt     Me   0                                         2-26     H        2-CarOEt     Me   0                                         2-27     Me       Mec--CH.sub.2 --                                                                           Me   0                                         2-28     H        Mec--CH.sub.2 --                                                                           Me   0                                         2-29     Me       Et           Et   0                                         2-30     H        Et           Et   0                                         ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Cpd.                                                                          No.      R.sup.1 R.sup.3   R.sup.4 m   n                                      ______________________________________                                        3-1      Me      Me        Me      1   3                                      3-2      H       Me        Me      1   3                                      3-3      Me      2-FEt     Me      1   3                                      3-4      H       2-FEt     Me      1   3                                      3-5      Me      Et        Me      1   3                                      3-6      H       Et        Me      1   3                                      3-7      Me      --CH.sub.2 Car                                                                          Me      1   3                                      3-8      H       --CH.sub.2 Car                                                                          Me      1   3                                      3-9      Me      --CH.sub.2 Ac                                                                           Me      1   3                                      3-10     H       --CH.sub.2 Ac                                                                           Me      1   3                                      3-11     Me      Me        Me      1   1                                      3-12     H       Me        Me      1   1                                      3-13     Me      Me        Me      2   3                                      3-14     H       Me        Me      2   3                                      3-15     Me      --CH.sub.2 Car                                                                          Me      1   1                                      3-16     H       --CH.sub.2 Car                                                                          Me      1   1                                      3-17     Me      Et        Me      1   1                                      3-18     H       Et        Me      1   1                                      3-19     Me      2-FEt     Me      1   1                                      3-20     H       2-FEt     Me      1   1                                      3-21     Me      Et        Et      1   1                                      3-22     H       Et        Et      1   1                                      ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Cpd.                                                                          No.        R.sup.1  Z                                                         ______________________________________                                        4-1        Me       --(CH.sub.2).sub.3 --                                     4-2        H        --(CH.sub.2).sub.3 --                                     4-3        Me       --(CH.sub.2).sub.4 --                                     4-4        H        --(CH.sub.2).sub.4 --                                     4-5        Me       --(CH.sub.2).sub.2 --O--CH.sub.2 --                       4-6        H        --(CH.sub.2).sub.2 --O--CH.sub.2 --                       4-7        Me       --(CH.sub.2).sub.2 --S--CH.sub.2 --                       4-8        H        --(CH.sub.2).sub.2 --S--CH.sub.2 --                       4-9        Me       --(CH.sub.2).sub.2 --NMe--CH.sub.2 --                     4-10       H        --(CH.sub.2).sub.2 --NMe--CH.sub.2 --                     4-11       Me       --(CH.sub.2).sub.2 --NAc--CH.sub.2 --                     4-12       H        --(CH.sub.2).sub.2 --NAc--CH.sub.2 --                     4-13       Me       --(CH.sub.2).sub.2 --NH--CH.sub.2 --                      4-14       H        --(CH.sub.2).sub.2 --NH--CH.sub.2 --                      4-15       Me       --(CH.sub.2).sub.2 -- NH--CO--                            4-16       H        --(CH.sub.2).sub.2 --NH--CO--                             4-17       Me       --(CH.sub.2).sub.2 --NMe--CO--                            4-18       H        --(CH.sub.2).sub.2 --NMe--CO--                            4-19       Me       --CH.sub.2 --CO--NH--CO--                                 4-20       H        --CH.sub.2 --CO--NH--CO--                                 4-21       Me       --CH.sub.2 --CHMe--O--CH.sub.2 --                         4-22       H        --CH.sub.2 --CHMe--O--CH.sub.2 --                         4-23       Me       --CH.sub.2 --CHMe--CH.sub.2 --                            4-24       H        --CH.sub.2 --CHMe--CH.sub.2 --                            4-25       Me       --(CH.sub.2).sub.2 --CHOH--                               4-26       H        --(CH.sub.2).sub.2 --CHOH--                               4-27       Me       --(CH.sub.2).sub.2 --CHF--                                4-28       H        --(CH.sub.2).sub.2 --CHF--                                ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        Cpd.                                                                          No.      R.sup.1 R.sup.2  R.sup.3 R.sup.4                                                                            l                                      ______________________________________                                        5-1      Me      OH       Me      Me   1                                      5-2      H       OH       Me      Me   1                                      5-3      Me      F        Me      Me   1                                      5-4      H       F        Me      Me   1                                      5-5      Me      --NH.sub.2                                                                             Me      Me   1                                      5-6      H       --NH.sub.2                                                                             Me      Me   1                                      5-7      Me      --NHAc   Me      Me   1                                      5-8      H       --NHAc   Me      Me   1                                      5-9      Me      MeO      Me      Me   1                                      5-10     H       MeO      Me      Me   1                                      5-11     Me      EtO      Me      Me   1                                      5-12     H       EtO      Me      Me   1                                      5-13     Me      CarO     Me      Me   1                                      5-14     H       CarO     Me      Me   1                                      5-15     Me      CN       Me      Me   1                                      5-16     H       CN       Me      Me   1                                      5-17     Me      Car      Me      Me   1                                      5-18     H       Car      Me      Me   1                                      5-19     Me      MeCar    Me      Me   1                                      5-20     H       MeCar    Me      Me   1                                      5-21     Me      diMeCar  Me      Me   1                                      5-22     H       diMeCar  Me      Me   1                                      5-23     Me      Mec      Me      Me   1                                      5-24     H       Mec      Me      Me   1                                      5-25     Me      Me       Me      Me   1                                      5-26     H       Me       Me      Me   1                                      5-27     Me      Et       Me      Me   1                                      5-28     H       Et       Me      Me   1                                      5-29     Me      AcO      Me      Me   1                                      5-30     H       AcO      Me      Me   1                                      5-31     Me      --CH.sub.2 Ac                                                                          Me      Me   1                                      5-32     H       --CH.sub.2 Ac                                                                          Me      Me   1                                      5-33     Me      MeS      Me      Me   1                                      5-34     H       MeS      Me      Me   1                                      5-35     Me      MeS(O)-- Me      Me   1                                      5-36     H       MeS(O)-- Me      Me   1                                      5-37     Me      MeSO.sub.2 --                                                                          Me      Me   1                                      5-38     H       MeSO.sub.2 --                                                                          Me      Me   1                                      ______________________________________                                    

                  TABLE 6                                                         ______________________________________                                        Cpd.                                                                          No.     R.sup.1 R.sup.3                                                                              R.sup.4                                                                              Z'         m                                    ______________________________________                                        6-1     Me      Me     Me     --CH.sub.2 O(CH.sub.2).sub.2 --                                                          0                                    6-2     H       Me     Me     --CH.sub.2 O(CH.sub.2).sub.2 --                                                          0                                    6-3     Me      Me     Me     --O(CH.sub.2).sub.2 --                                                                   1                                    6-4     H       Me     Me     --O(CH.sub.2).sub.2 --                                                                   1                                    6-5     Me      Me     Me     --CH.sub.2 S(CH.sub.2).sub.2 --                                                          0                                    6-6     H       Me     Me     --CH.sub.2 S(CH.sub.2).sub.2 --                                                          0                                    6-7     Me      Me     Me     --S(CH.sub.2).sub.2 --                                                                   1                                    6-8     H       Me     Me     --S(CH.sub.2).sub.2 --                                                                   1                                    6-9     Me      Me     Me     --CH.sub.2 NMe(CH.sub.2).sub.2 --                                                        0                                     6-10   H       Me     Me     --CH.sub.2 NMe(CH.sub.2).sub.2 --                                                        0                                     6-11   Me      Me     Me     --CH.sub.2 NAc(CH.sub.2).sub.2 --                                                        0                                     6-12   H       Me     Me     --CH.sub.2 NAc(CH.sub.2).sub.2 --                                                        0                                     6-13   Me      Me     Me     --NAc(CH.sub.2).sub.2 --                                                                 1                                     6-14   H       Me     Me     --NAc(CH.sub.2).sub.2 --                                                                 1                                    ______________________________________                                    

                  TABLE 7                                                         ______________________________________                                        Cpd.                                  position                                No.     R.sup.1 R.sup.3  Z"       m   of bond                                 ______________________________________                                        7-1     Me      Me       --(CH.sub.2).sub.2 --                                                                  2   *                                       7-2     H       Me       --(CH.sub.2).sub.2 --                                                                  2   *                                       7-3     Me      Me       --CH.sub.2 --                                                                          3   *                                       7-4     H       Me       --CH.sub.2 --                                                                          3   *                                       7-5     Me      Me       --(CH.sub.2).sub.2 --                                                                  2   **                                      7-6     H       Me       --(CH.sub.2).sub.2 --                                                                  2   **                                      7-7     Me      Et       --(CH.sub.2).sub.2 --                                                                  2   *                                       7-8     H       Et       --(CH.sub.2).sub.2 --                                                                  2   *                                       7-9     Me      2-FEt    --(CH.sub.2).sub.2 --                                                                  2   *                                        7-10   H       2-FEt    --(CH.sub.2).sub.2 --                                                                  2   *                                       ______________________________________                                    

                  TABLE 8                                                         ______________________________________                                        Cpd.                                                                          No.      R.sup.3 R.sup.5            p                                         ______________________________________                                        8-1      H       Na                 2                                         8-2      H       Dox                2                                         8-3      H       Na                 1                                         8-4      H       PivO-CH.sub.2 --   1                                         8-5      H       --CH.sub.2 O--CO--(1-Me-- -cHx)                                                                  1                                         8-6      H       --CH(Me)O--CO--O-- -cPn                                                                          1                                         8-7      H       --CH(Me)O--CO--O-- .sub.- iPr                                                                    1                                         8-8      H       --CH(Me)O--CO--O--Men                                                                            1                                         8-9      H       --CH(Me)O--CO--O--CH.sub.2  -cHx                                                                 1                                         8-10     H       --CH(Me)O--CO--O-- -cHx                                                                          1                                         8-11     H       --CH(Me)O--CO-- -cHx                                                                             1                                         8-12     H       --CH.sub.2 OAc     1                                         8-13     H       1-EtcOEt           1                                         8-14     H       1-PivOEt           1                                         8-15     H       Dox                1                                         8-16     H       Phth               1                                         8-17     Me      PivO--CH.sub.2 --  1                                         8-18     Me      --CH.sub.2 O--CO--(1-Me-- -cHx)                                                                  1                                         8-19     Me      --CH(Me)O--CO--O-- -cPn                                                                          1                                         8-20     Me      --CH(Me)O--CO--O-- .sub. - iPr                                                                   1                                         8-21     Me      --CH(Me)O--CO--O--CH.sub.2  -cHx                                                                 1                                         8-22     Me      --CH(Me)O--CO--O-- -cHx                                                                          1                                         8-23     Me      --CH(Me)O--CO-- -cHx                                                                             1                                         8-24     Me      --CH.sub.2 OAc     1                                         8-25     Me      1-EtcOEt           1                                         8-26     Me      1-PivOEt           1                                         8-27     Me      Dox                1                                         8-28     Me      Phth               1                                         8-29     H       Na                 3                                         8-30     H       PivO--CH.sub.2 --  3                                         8-31     H       1-EtcOEt           3                                         8-32     H       Dox                3                                         8-33     H       Phth               3                                         8-34     H       PivO--CH.sub.2 --  2                                         8-35     H       1-EtcOEt           2                                         ______________________________________                                    

                  TABLE 9                                                         ______________________________________                                        Cpd.                                                                          No.     R.sup.3    R.sup.5                                                    ______________________________________                                        9-1     H          Na                                                         9-2     H          PivO--CH.sub.2 --                                          9-3     H          --CH.sub.2 O--CO--(1-Me-- -cHx)                            9-4     H          --CH.sub.2 O--CO--O--Men                                   9-5     H          --CH(Me)O--CO-- -cPn                                       9-6     H          --CH(Me)O--CO--O-- .sub.- iPr                              9-7     H          --CH(Me)O--CO--O--Men                                      9-8     H          --CH(Me)O--CO--O--CH.sub.2 -- -cHx                         9-9     H          --CH(Me)O--CO--O-- -cHx                                    9-10    H          --CH(Me)O--CO--O--tBu                                      9-11    H          --CH(Me)O--CO-- -cHx                                       9-12    H          1-PivOEt                                                   9-13    H          --CH.sub.2 OAc                                             9-14    H          1-EtcOEt                                                   9-15    H          --CH(Me)O--CO--O--CHEt.sub.2                               9-16    H          --CH(Me)O--CO--O--CPr.sub.3                                9-17    H          --CH(Me)O--CO--O-- -cHp                                    9-18    H          Dox                                                        9-19    H          Phth                                                       9-20    H          Pdox                                                       9-21    H          1-AcOEt                                                    9-22    H          1- .sub.- iByrOEt                                          9-23    H          --CH.sub.2 O--CO--(1-Me--  -cPn)                           9-24    H          1-MecOEt                                                   9-25    H          --CH(Me)O--CO--O--Ada                                      9-26    Me         PivO--CH.sub.2 --                                          9-27    Me         --CH.sub.2 O--CO--(1-Me-- -cHx)                            9-28    Me         --CH(Me)O--CO--O-- -cPn                                    9-29    Me         --CH(Me)O--CO--O-- .sub.- iPr                              9-30    Me         --CH(Me)O--CO--O--Men                                      9-31    Me         --CH(Me)O--CO--O--CH.sub.2 -- -cHx                         9-32    Me         --CH(Me)O--CO--O-- -cHx                                    9-33    Me         --CH(Me)O--CO-- -cHx                                       9-34    Me         --CH.sub.2 OAc                                             9-35    Me         1-EtcOEt                                                   9-36    Me         1-PivOEt                                                   9-37    Me         Dox                                                        9-38    Me         Na                                                         9-39    Me         Phth                                                       9-40    Ac         PivO--CH.sub.2 --                                          9-41    Ac         1-EtcOEt                                                   9-42    Ac         Dox                                                        9-43    Ac         Phth                                                       9-44    Et         PivO--CH.sub.2 --                                          9-45    Et         1-EtcOEt                                                   9-46    Et         Dox                                                        9-47    Et         Na                                                         9-48    Ac         Na                                                         9-49    H          --CH(Me)O--CO--O-- .sub.- sBu                              9-50    H          1-AcOEt                                                    9-51    H          --CH.sub.2 O--CO--O--CH.sub.2 -- -cPr                      9-52    H          --CH.sub.2 O--CO--O--CH.sub.2 --  -cBu                     9-53    H          --CH(Me)O--CO--O--CH.sub.2 -- -cPn                         9-54    H          2-oxo-4,5,6,7-tetrahydro-                                                     1,3-benzodioxolen-4-yl                                     9-55    H          5- .sub.- iPr--Dix--CH.sub.2 --                            9-56    H          5- .sub.- tBu--Dix--CH.sub.2 --                            9-57    H          1-(5-Me--Dix)Et                                            9-58    H          1-( .sub.- iPrO--CO--O--)Et                                9-59    H          2-Me-1-( .sub.- iPrO--CO--O--)Pr                           9-60    H          2-( .sub.- iPrO--CO--O--)Pr                                9-61    H          1-PivOPr                                                   9-62    H          2-Me-1-PivOPr                                              9-63    H          2-PivOPr                                                   9-64    H          1-(1-Me -cHx--CO--O--)Pr                                   9-65    H          2-Me-1-(1-Me -cHx--CO--O--)Pr                              9-66    H          2-(1-Me -cHx--CO--O--)Pr                                   9-67    H          1-( -cHx--CO--O--)Pr                                       9-68    H          2-Me-1-( -cHx--CO--O--)Pr                                  9-69    H          ( -cHx--AcO)--CH.sub.2 --                                  9-70    H          1-( -cHx--AcO)Et                                           9-71    H          1-( -cHx--AcO)Pr                                           9-72    H          2-Me-1-( -cHx--AcO)Pr                                      9-73    H          1- .sub.- iByrOEt                                          9-74    H          1- .sub. - iByrOPr                                         9-75    H          ( -cPn--CO--O--)CH.sub.2 --                                9-76    H          1-( -cPn--CO--O--)Et                                       9-77    H          1-( -cPn--CO--O--)Pr                                       9-78    H          2-Me-1-( -cPn--CO--O--)Pr                                  9-79    H          1-AcOPr                                                    9-80    H          1-AcO-2-MePr                                               9-81    H          PrnO--CH.sub.2 --                                          9-82    H          1-PrnOEt                                                   9-83    H          1-PrnOPr                                                   9-84    H          1-(1-Me -cPn--CO--O--)Et                                   9-85    H          1-(1-Me -cPn--CO--O--)Pr                                   9-86    H          2-AcOPr                                                    9-87    H          ByrO--CH.sub.2 --                                          9-88    H          1-ByrOEt                                                   9-89    H           .sub.- iPrO.CO.OCH.sub.2 --                               9-90    H           -cPnO.CO.OCH.sub.2 --                                     9-91    H           -cHxO.CO.OCH.sub.2 --                                     9-92    H           .sub.- tBuO.CO.OCH.sub.2 --                               9-93    H          EtO.CO.OCH.sub.2 --                                        9-94    H          MeO.CO.OCH.sub.2 --                                        9-95    Me          -cHx.CO.OCH.sub.2 --                                      9-96    Me          -cPnO.CO.OCH.sub.2 --                                     9-97    Me          -cHxO.CO.OCH.sub.2 --                                     9-98    Me          .sub.- iPrO.CO.OCH.sub.2 --                               9-99    Me          .sub.- iByrOCH.sub.2 --                                    9-100  Me         1-( .sub.- iByrO)Et                                         9-101  Me         1-( -cPn.CO.O)Et                                            9-102  Me          -cPn.CO.OCH.sub.2 --                                       9-103  H           -cHx.CO.OCH.sub.2 --                                      ______________________________________                                    

Of the compounds listed above, the following are preferred, that is tosay Compounds No. 1-1, 1-2, 1-9, 1-23, 1-267, 1-269, 1-275, 9-2, 9-3,9-5, 9-6 and 9-8, of which the following are most preferred:

1-1.2-(2-Carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate,especially its (1R, 5S, 6S)-2-[(2S,4S)-2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateisomer;

1-2.2-(2-Carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-carbapen-2-em-3-carboxylate,especially its (5R, 6S)-2-[(2S,4S)-2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-carbapen-2-em-3-carboxylateisomer;

1-23.2-(1,1-Dimethyl-2-dimethylcarbamoylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate,especially its (1R, 5S, 6S)-2-[(2S,4S)-1,1-dimethyl-2-dimethylcarbamoylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateisomer;

1-267.2-(1,1-Dimethyl-2-ethylcarbamoylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate,especially its (1R, 5S, 6S)-2-[(2S,4S)-1,1-dimethyl-2-ethylcarbamoylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateisomer;

1-275.2-(2-Cyclopropylcarbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate,especially its (1R, 5S, 6S)-2-[(2S,4S)-2-cyclopropylcarbamoyl-1,1-dimethylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate isomer;

9-2. Pivaloyloxymethyl2-(2-oxo-4-pyrrolidinylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate,especially its pivaloyloxymethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateisomer;

9-3. (1-Methylcyclohexan-1-yl)carbonyloxymethyl2-(2-oxo-4-pyrrolidinylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate,especially its (1-methylcyclohexan-1-yl)carbonyloxymethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateisomer;

9-5. 1-(Cyclopentyloxycarbonyloxy)ethyl2-(2-oxo-4-pyrrolidinylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate,especially its 1-(cyclopentyloxycarbonyloxy)ethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateisomer;

and pharmaceutically acceptable salts thereof.

The compounds of the present invention can be prepared by a variety ofmethods well known for preparing this type of compound. For example, ingeneral terms, the compounds may be prepared by reacting a compound offormula (IV): ##STR34## (in which R¹ is as defined above, R²⁷ representsa group of formula --OR²⁹ or --SO--R³⁰, in which:

R²⁹ represents an alkanesulfonyl group, an arylsulfonyl group, adialkylphosphoryl group, or a diarylphosphoryl group; and

R³⁰ represents an alkyl group, a haloalkyl group, a 2-acetylaminoethylgroup, a 2-acetylaminovinyl group; an aryl group or a heteroaryl group(i.e. an aromatic heterocyclic group); and

R²⁸ represents a protecting group for a carboxylic acid); with acompound of formula (Va):

    HS--(CH.sub.2).sub.l --R.sup.II X.sup.-                    (Va)

or with a compound of formula (Vb):

    HS--(CH.sub.2).sub.l --R.sup.III                           (Vb)

[in which R^(II) represents said group of formula (II), in which, ifrequired any active groups are protected, R^(III) represents said groupof formula (III), in which, if required any active groups are protected,l is as defined above, and X⁻ is a balancing anion],

to give a compound of formula (VI): ##STR35## [in which R¹, R²⁸ and lare as defined above, and R^(b) represents said group of formula (II) or(III), in which, if required any active groups are protected, and which,if necessary contains a balancing anion], and then, if necessary,removing protecting groups and/or esterifying and/or salifying theresulting compound to give a compound of formula (I) or apharmaceutically acceptable salt or ester thereof.

In the above formulae, R²⁹ represents: an alkanesulfonyl group, such asa methanesulfonyl, ethanesulfonyl, propanesulfonyl, isopropanesulfonylor butanesulfonyl group; an arylsulfonyl group, such as aphenylsulfonyl, tolylsulfonyl, especially p-tolylsulfonyl, ornaphthylsulfonyl group; a dialkylphosphoryl group, such as adimethylphosphoryl, diethylphosphoryl, dipropylphosphoryl,diisopropylphosphoryl, dibutylphosphoryl or dipentylphosphoryl group; ora diarylphosphoryl group, such as a diphenylphosphoryl orditolylphosphoryl group;

R³⁰ represents an alkyl group, such as a methyl, ethyl, propyl orisopropyl group; a haloalkyl group, such as a fluoromethyl,chloromethyl, fluoroethyl, difluoromethyl, difluoroethyl, dichloroethyl,trifluoromethyl or trifluoroethyl group; a 2-acetylaminoethyl group; a2-acetylaminovinyl group; an aryl group, such as a phenyl or naphthylgroup which may optionally be substituted with from 1 to 3 substituents,which may be the same or different and examples of the substituentinclude the fluorine, chlorine and bromine atoms, and the methyl, ethyl,propyl, isopropyl, methoxy, ethoxy, propoxy, isopropoxy,methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, nitro, hydroxy andcyano groups; a heteroaryl group such as a pyridyl or pyrimidinyl groupwhich may optionally be substituted with from 1 to 3 substituents, whichmay be the same or different and examples of the substituent include thefluorine, chlorine and bromine atoms and the methyl, ethyl, propyl andisopropyl groups; and

R²⁸ represents a protecting group for a carboxylic acid, examples of theprotecting group include, for example an alkyl group such as a methyl,ethyl or t-butyl group; an aralkyl group such as a benzyl,diphenylmethyl, 4-nitrobenzyl or 2-nitrobenzyl group; an alkenyl groupsuch as an allyl, 2-chloroallyl or 2-methylally group; a haloalkyl groupsuch as a 2,2,2-trichloroethyl, 2,2-dibromoethyl or 2,2,2-tribromoethylgroup or a 2-trimethylsilylethyl group.

In more detail, the compounds may be prepared as illustrated in thefollowing Methods A and B.

Method A

This is as shown in the following Reaction Scheme A: ##STR36##

In the above formulae:

R¹, R⁵, R^(a), R^(b), R²⁸, R²⁸ and l are as defined above.

In the compound of formula (Va), X⁻ represents a balancing anion, whichis preferably a halogen atom (e.g. a chlorine, bromine or iodine atom)or an alkylsulfonyloxy, arylsulfonyloxy or halosulfonyloxy group (e.g. amethanesulfonyloxy, p-toluenesulfonyloxy, trifluoromethanesulfonyloxy orfluorosulfonyloxy group).

In Step A1 of this reaction scheme, the compound of formula (VII), whichis the starting material, is reacted with an active derivative of analkanesulfonic, arylsulfonic, dialkylphosphoric or diarylphosphoric acidR²⁹ OH, e.g. an alkanesulfonic or arylsulfonic acid anhydride or adialkylphosphoryl or diarylphosphoryl halide in the presence of a base.In Step A2, the resulting compound of formula (VIII) is then reactedwithout isolation with a mercaptan derivative of formula (Va) or (Vb) inthe presence of a base to give a compound of formula (VI). The desiredcompound of formula (I) may then be prepared, if necessary, by removalof the protecting group, R²⁸, from the carboxyl group in the compound offormula (VI).

In Step A1, examples of the reactive derivative of the reagent offormula R²⁹ OH which may be employed include: alkanesulfonic acidanhydrides, such as methanesulfonic or ethanesulfonic acid anhydride;arylsulfonic acid anhydrides, such as benzenesulfonic orp-toluenesulfonic acid anhydride; dialkylphosphoryl halides, such asdimethylphosphoryl or diethylphosphoryl chloride; diarylphosphorylhalides, such as diphenylphosphoryl chloride or diphenylphosphorylbromide. Of these reagents, p-toluenesulfonic acid anhydride ordiphenylphosphoryl chloride is preferred. There is no particularrestriction on the nature of the solvent to be employed, provided thatit has no adverse effect on the reaction or on the reagents involved.Examples of suitable solvents include: halogenated hydrocarbons,especially halogenated aliphatic hydrocarbons, such as methylenechloride, 1,2-dichloroethane or chloroform; nitriles such asacetonitrile; amides such as N,N-dimethylformamide orN,N-dimethylacetamide. There is likewise no particular limitation on thenature of the base to be employed, provided that it has no adverseeffect upon other parts of the molecule, particularly the β-lactam ring.Preferred bases which may be employed in this reaction include suchorganic bases as triethylamine, diisopropylethylamine or4-dimethylaminopyridine.

The reaction can take place over a wide range of temperatures, and theprecise reaction temperature is not critical to the invention. Ingeneral, we find it convenient to carry out the reaction at a relativelylow temperature in order to prevent side reactions, usually at atemperature from -20° C. to 40° C. The time required for the reactionmay also vary widely, depending on many factors, notably the reactiontemperature and the nature of the reagents. However, provided that thereaction is effected under the preferred conditions outlined above, aperiod of from 10 minutes to 5 hours will usually suffice.

It is not necessary to isolate the resulting compound of formula (VIII)before the next step in the reaction scheme. Thus, in Step A2, thereaction mixture may be treated with a mercaptan derivative of formula(Va) or (Vb) in the presence of a base. The nature of the base to beemployed in the reaction is not critical but preferred bases includeorganic bases, such as triethylamine or diisopropylamine, and inorganicbases, such as potassium carbonate or sodium carbonate.

The reaction can take place over a wide range of temperatures, and theprecise reaction temperature is not critical to the invention. Ingeneral, however, we find it best to carry out the reaction at arelatively low temperature, e.g. at a temperature from -20° C. to roomtemperature. The time required for the reaction may also vary widely,depending on many factors, notably the reaction temperature and thenature of the reagents. However, provided that the reaction is effectedunder the preferred conditions outlined above, a period of from 30minutes to 5 days will usually suffice.

After completion of the reaction, the desired compound of formula (VI)may be recovered from the reaction mixture by conventional means, forexample, one suitable recovery procedure comprises simply distilling offthe solvent from the reaction mixture. The resulting compound may befurther purified, if necessary, by conventional means, for example byrecrystallization, reprecipitation or the various chromatographytechniques, such as column chromatography or preparative thin layerchromatography.

If desired, before or after such further purification, thecarboxy-protecting group may be removed. This is preferably effectedwithout isolation of the compound of formula (VI).

The final reaction step of process A comprises the removal of thecarboxy-protecting group R²⁸ from the compound of formula (VI), to givethe corresponding carboxylic acid of formula (I), and, if required,conversion of the resulting free acid to another salt or ester. Thisstep is optional, and it will be appreciated that the removal of thecarboxy-protecting group may not always be necessary or desired, forexample when the compound of formula (VI) is a pharmaceuticallyacceptable ester within the scope of the present invention. If it isdesired to remove the carboxy-protecting group, this may be done by theuse of conventional methods, the choice of which will depend upon thenature of the protecting group employed.

If the protecting group is removable by reduction, for example if it isa haloalkyl group, an aralkyl group or a benzhydryl group, it may beremoved by contact with a reducing agent. In the case of haloalkylgroups, such as the 2,2-dibromoethyl or 2,2,2-trichloroethyl groups, thepreferred reducing agent is a combination of zinc with acetic acid. Ifthe protecting group is an aralkyl group (such as a benzyl orp-nitrobenzyl group) or a benzhydryl group, it is preferred to remove iteither by catalytic reduction using hydrogen and a suitable catalyst,such as platinum or palladium on carbon; or by reduction with an alkalimetal sulfide, such as sodium sulfide or potassium sulfide. Whatever thereduction technique, the reduction process is preferably effected in thepresence of a solvent, the nature of which is not critical, providedthat it has no adverse effect upon the reaction. Suitable solventsinclude alcohols (such as methanol or ethanol), ethers (such astetrahydrofuran or dioxane), aliphatic carboxylic acids (such as aceticacid), or a mixture of one or more of these organic solvents with water.The reaction temperature is not critical but will normally be in therange from 0° C. to room temperature. The time required for the reactionwill vary, depending upon the nature of the starting materials andreducing agents, as well as upon the reaction temperature, but a periodof from 5 minutes to 12 hours will normally suffice.

After completion of the reaction, the desired compound, which willcontain a free carboxy group, may be recovered by conventional meansfrom the reaction mixture. For example, a suitable recovery techniquecomprises: separating of any insolubles; and then distilling off thesolvent to give the desired product. This may, if necessary, be furtherpurified by conventional means, for example recrystallization or thevarious chromatography techniques, such as preparative thin layerchromatography or column chromatography.

If desired, a carboxy group in the compound prepared as described abovecan be converted to an ester group hydrolysable under physiologicalconditions. This may be effected by conventional means. If R⁵ representsan ester which is hydrolysable under physiological conditions, e.g. apivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl, methoxymethyl or2-oxo-5-methyl-1,3-dioxolen-4-ylmethyl group, the compounds of formula(I) can be hydrolyzed in vivo under physiological conditions.Accordingly such a compound may be administered directly to a patientwithout deprotection.

Method B

This is as shown in the following Reaction Scheme B: ##STR37##

In the above formulae R¹, R^(a), R^(b), R²⁸, R³⁰ and l are as definedabove.

The compounds of formula (IX) used as starting materials in thisreaction scheme can be prepared as described in Japanese PatentApplication Kokai No. Sho 62-30781.

In Step B1, the compound of formula (VI) can be prepared by reacting acompound of formula (IX) with a mercaptan compound of formula (Va) or(Vb) in the presence of a base and in an inert solvent. There is noparticular restriction on the nature of the solvent to be employed,provided that it has no adverse effect on the reaction or on thereagents involved. Examples of suitable solvents include: ethers, suchas tetrahydrofuran; nitriles, such as acetonitrile; fatty acid amides,such as dimethylformamide; sulfoxides, such as dimethyl sulfoxide;water; or a mixture of any two or more thereof. The base used in thereaction is likewise not critical, provided that it does not affectother parts of the molecule, particularly the β-lactam ring. Examples ofsuitable bases include: organic bases, such as diisopropylethylamine,triethylamine, N-methylpiperidine or 4-(N,N-dimethylamino)pyridine; andinorganic bases, particularly alkali metal carbonates, such as potassiumcarbonate or sodium bicarbonate. The reaction can take place over a widerange of temperature, and the precise reaction temperature is notcritical to the invention, although we prefer that the reaction iscarried out at relatively low temperature in order to prevent sidereactions. In general, we find it convenient to carry out the reactionat a temperature from -20° C. to 40° C. The time required for thereaction may also vary widely, depending on many factors, notably thereaction temperature and the nature of the reagents. However, providedthat the reaction is effected under the preferred conditions outlinedabove, a period of from 5 minutes to 5 days will usually suffice.

After completion of the reaction, the desired compound of formula (VI)can be recovered from the reaction mixture by conventional means. Also,the compounds of formula (I) can, if necessary, be prepared bydeprotection of a compound of formula (VI) using the procedure describedin Method A. Further separation and purification of the resultingcompound may be effected as described in Method A.

Compounds of formula (Va) and (Vb), which are also starting materials inthe above reaction schemes may be obtained by conventional and wellknown means for preparing this type of compound. In the case of thosecompounds of formula (Vb), where these are not otherwise available, theymay be prepared as follows:

First, a compound of formula (X):

    L--R.sup.c                                                 (X)

[in which L represents a leaving group, such as a hydroxy group, ahalogen atom (such as a chlorine, bromine or iodine atom) or asulfonyloxy group (e.g. a methanesulfonyloxy, propanesulfonyloxy,trifluoromethanesulfonyloxy or toluenesulfonyloxy group) and R^(c)represents a 2-oxopyrrolidinyl group, as defined in relation to thegroup of formula (III)] is converted to the corresponding protected thiocompound of formula (XI):

    R.sup.d --R.sup.c                                          (XI)

[in which R^(d) represents a thio-protecting group such as an alkanoylgroup (e.g. an acetyl or propionyl group) or an aralkyl group (e.g. a4-methoxybenzyl, 3,4-dimethoxybenzyl, benzhydryl, triphenylmethyl ordi(4-methoxyphenyl)methyl group)].

When L represents a hydroxy group, this may be performed by means of theMitsunobu reaction, which may be performed under conditions known perse, in the presence of diethyl azodicarboxylate, triphenyl phosphine andthioacetic acid.

When L represents a halogen atom or a sulfonyloxy group, the reactionmay be performed by reacting the compound of formula (X) with a sodiumor potassium salt of R^(d) --SH.

The second step is a conventional hydrolysis reaction and may beperformed under conditions known per se. For example, when R^(d) is analkanoyl group, it may be removed under alkaline or acidic conditions,for example, with sodium hydroxide in aqueous methanol. When R^(d) is anaralkyl group, it may be removed, e.g. with trifluoromethanesulfonicacid in the presence of trifluoroacetic acid and anisole.

The mercaptan compound of formula (Va) may be prepared as illustrated inthe following Reaction Scheme C: ##STR38##

In the above formulae, R³¹ represents a mercapto-protecting group, suchas an aralkyl group [e.g. a 4-methoxybenzyl, triphenylmethyl,benzhydryl, 3,4-dimethoxybenzyl or di(4-methoxyphenyl)methyl group], analkanoyl group (e.g. an acetyl, propionyl or pivaloyl group) or anaromatic acyl group (e.g. an o- or p-toluoyl group or a benzoyl group);L represents a leaving group, such as a halogen atom (e.g. a chlorine,fluorine or iodine atom) or a sulfonyloxy group (e.g. amethanesulfonyloxy, toluenesulfonyloxy, trifluoromethanesulfonyloxy orfluorosulfonyloxy group); and R², R³, R⁴, l, m, n and X⁻ are as definedabove.

The compound of formula (XII) used as the starting material in thisreaction scheme may be prepared by known methods, for example, asdescribed in Japanese Patent Application Kokai No. Sho 60-233076.

In Step C1, a compound of formula (XIII) is prepared by reacting thecompound of formula (XII) with a compound of formula R³ --L (XV) in thepresence of a base. Alternatively, where R³ is a methyl group, thecompound of formula (XII) is reacted with formaldehyde (normally in theform of formalin or paraformaldehyde) and then with sodiumcyanoborohydride; or it may be reacted with formaldehyde and thereaction product may then be subjected to catalytic hydrogenation withpalladium-on-charcoal; or it may be reacted with formaldehyde and formicacid, with heating.

The reaction is preferably carried out in the presence of an inertsolvent. There is no particular restriction on the nature of the solventto be employed, provided that it has no adverse effect on the reactionor on the reagents involved. Examples of suitable solvents include:amides, especially fatty acid amides, such as N,N-dimethylformamide orN,N-dimethylacetamide; halogenated hydrocarbons, especially halogenatedaliphatic hydrocarbons, such as methylene chloride, 1,2-dichloroethaneor chloroform; ethers such as tetrahydrofuran, dioxane or diethyl ether;nitriles such as acetonitrile; and mixtures of any one or more of thesesolvents with water.

The reaction can take place over a wide range of temperatures, and theprecise reaction temperature is not critical to the invention. Ingeneral, we find it convenient to carry out the reaction at atemperature from -20° C. to 100° C., but the reaction is preferablyeffected at a relatively low temperature, in order to avoid sidereactions. The time required for the reaction may also vary widely,depending on many factors, notably the reaction temperature and thenature of the reagents. However, provided that the reaction is effectedunder the preferred conditions outlined above, a period of from 10minutes to 2 days will usually suffice.

In Step 2 of this reaction scheme, the compound of formula (XIII) isreacted with a compound of formula R⁴ --X (XVI). The reaction ispreferably carried out in the presence of an inert solvent. There is noparticular restriction on the nature of the solvent to be employed,provided that it has no adverse effect on the reaction or on thereagents involved. Examples of suitable solvents include: aromatichydrocarbons, such as benzene, toluene or xylene; halogenatedhydrocarbons, especially halogenated aliphatic hydrocarbons, such asmethylene chloride, 1,2-dichloroethane or chloroform; amides, especiallyfatty acid amides, such as N,N-dimethylformamide orN,N-dimethylacetamide; ethers such as tetrahydrofuran, dioxane ordiethyl ether; nitriles such as acetonitrile; and mixtures of any one ormore of these solvents with water.

The reaction can take place over a wide range of temperatures, and theprecise reaction temperature is not critical to the invention. Ingeneral, we find it convenient to carry out the reaction at atemperature from -20° C. to 180° C., but the reaction is preferablyeffected at a relatively low temperature, in order to avoid sidereactions. The time required for the reaction may also vary widely,depending on many factors, notably the reaction temperature and thenature of the reagents. However, provided that the reaction is effectedunder the preferred conditions outlined above, a period of from 10minutes to 3 days will usually suffice.

In Step C3 of the reaction scheme, the compound of formula (XIV),prepared as described in Step C2, is deprotected to afford a compound offormula (Va).

The method of deprotection will vary, depending on the nature of theprotecting group R³¹. Thus, where R³¹ is an aralkyl group, thedeprotection may conveniently be carried out by reacting the compound offormula (XIV) with trifluoromethanesulfonic acid in the presence oftrifluoroacetic acid and anisole.

On the other hand, where R³¹ is an alkanoyl group or an aromatic acylgroup, the deprotection may conveniently be carried out by treating thecompound of formula (XIV) with hydrogen chloride or hydrogen bromide ina suitable solvent such as an alcohol (e.g. methanol or ethanol), wateror an aqueous ether (e.g. aqueous tetrahydrofuran or aqueous diethylether).

The reaction can take place over a wide range of temperatures, and theprecise reaction temperature is not critical to the invention. Ingeneral, we find it convenient to carry out the reaction at atemperature from -20° C. to 200° C., but the reaction is preferablyeffected at a relatively low temperature, in order to avoid sidereactions. The time required for the reaction may also vary widely,depending on many factors, notably the reaction temperature and thenature of the reagents. However, provided that the reaction is effectedunder the preferred conditions outlined above, a period of from 10minutes to 24 hours will usually suffice.

After completion of the reaction, the desired compound of formula (Va)may be recovered from the reaction mixture by conventional means, forexample, simply by distilling the solvent from the reaction mixture. Thedesired compound may be further purified, if necessary, by conventionalmeans such as reprecipitation or the various chromatographic techniques,such as column chromatography or preparative thin layer chromatography.

In the compound of formula (Va), the counteranion X⁻ will vary,depending on the nature of the reagent employed in Step C3.

The compounds of the present invention exhibit outstanding antibacterialactivity with a wide spectrum of activity, and they are also resistantto β-lactamase. As assessed by the agar plate dilution method, they havebeen shown to be active against a wide range of pathogenicmicroorganisms, including both Gram-positive bacteria (such asStaphylococcus aureus and Bacillus subtilis) and Gram-negative bacteria(such as Escherichia coli, Shigella flexneri, Klebsiella pneumoniae,Proteus vulgaris, Serratia species e.g. Serratia marcescens,Enterobacter species e.g. Enterobacter cloacae, Salmonella enteritidisand Pseudomonas aeruginosa) and are thus very useful for the treatmentof diseases caused by such microorganisms in humans and non-humananimals. Whereas thienamycin and its analogs are inactivated in vivo inmammals by dehydropeptidase I, the compounds of the invention are muchmore stable to this enzyme and exhibit good urinary recovery, and thuspossess good biological activity. They also exhibit low toxicity whentested in laboratory animals.

Table 10 sets out the activities of several of the compounds of thepresent invention against various bacteria, in terms of their minimalinhibitory concentrations (μg/ml).

                  TABLE 10                                                        ______________________________________                                                    Microorganism                                                     Cpd of Example                                                                              A           B       C                                           ______________________________________                                         1            0.01*       0.05    1.5                                          4            0.05        0.1     0.8                                         16            0.01*       0.05    1.5                                         20            0.02        0.1     0.8                                         36            0.01*       0.01*   25                                          ______________________________________                                         A: Staphylococcus aureus 209                                                  B: Escherichia coli NIHJ                                                      C: Pseudomonas aeruginosa 1001                                                0.01*: no higher than 0.01                                               

The results given above indicate that the compounds of the presentinvention may be used to treat or prevent diseases caused by a widerange of pathogenic bacteria.

The esters produced as described in Examples 39, 40 and 41 wereincubated at 37° C. for 1 hour with horse serum, after which the MICvalues were determined. The values were all exactly the same as those ofExample 36 and reported above. This means that the esters are easilycleaved by the esterase in the small intestines, after they have beenorally administered, and that they are thus absorbed well through thedigestive tract, and exhibit in full the activity possessed by the freeacid.

The compounds of the invention may be administered either orally orparenterally for the treatment of diseases in humans and other animalscaused by pathogenic microorganisms. The compounds may be formulatedinto any conventional forms for administration. For example, for oraladministration, suitable formulations include tablets, granules,capsules, powders and syrups, whilst formulations for parenteraladministration include injectable solutions for intramuscular or, morepreferably intravenous, injection.

The compounds of the invention are preferably administered parenterally,particularly in the form of an intravenous injection.

The dose of the compound of the invention will vary, depending upon theage, body weight and condition of the patient, as well as upon the formand times of administration. However, in general the adult daily dose isexpected to be from 100 to 3000 mg of the compound, which may beadministered in a single dose or in divided doses.

EXAMPLE 1 (1R, 5S, 6S)-2-[(2S, 4S)-2-Carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

(1) 5.14 ml of trifluoroacetic acid and 0.13 ml oftrifluoromethanesulfonic acid were added dropwise, whilst ice-cooling,to a suspension of 520 mg of (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)-1,1-dimethylpyrrolidiniumfluorosulfonate (prepared as described in Preparation 1) in 1.45 ml ofanisole, and the mixture was stirred at the same temperature for 40minutes. At the end of this time, the solvent was distilled off, and theresidue was washed repeatedly by decantation using diethyl ether anddried under reduced pressure to afford 420 mg of a (2S,4S)-2-carbamoyl-4-mercapto-1,1-dimethylpyrrolidinium salt as an oil. Theanion of this salt was not identified; the same applies hereafter.

(2) 0.20 ml of diisopropylethylamine and 0.24 ml of diphenylphosphorylchloride were added dropwise, whilst ice-cooling, to a solution of 400mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate in4 ml of dry acetonitrile, and the mixture was stirred at the sametemperature for 1 hour. At the end of this time, 0.46 ml ofdiisopropylethylamine and a solution of the salt prepared in step (1)above in 3 ml of acetonitrile were added to the reaction mixture, whilstice-cooling, and the mixture was then stirred for 7 hours and thenallowed to stand for 2 days at the same temperature. The solvent wasthen distilled off under reduced pressure, and the residue was washedrepeatedly by decantation using diethyl ether and dried under reducedpressure to afford a crude product. This crude product was thendissolved in a mixture of 30 ml of tetrahydrofuran and 30 ml of a 0.1Mphosphate buffer (pH 7.0) and hydrogenated at room temperature for 2.5hours in the presence of 555 mg of 10% w/w palladium-on-charcoal. At theend of this time, an insoluble material was removed by filtration withthe help of a Celite (trade mark) filter aid, and the filtrate waswashed with diethyl ether. The aqueous layer was then concentrated byevaporation under reduced pressure. The residue was adsorbed on a columnof Diaion (trade mark) HP-20AG (Mitsubishi Chemical Industries, Ltd.)and the fractions eluted with a 5% by volume aqueous acetone solutionwere concentrated by evaporation under reduced pressure, and the residuewas lyophilized to afford a crude product as a yellow powder. This crudeproduct was purified by chromatography using a Lobar column (Merck Co.,LiChroprep RP-8, size B). The fractions eluted with 5% and 10% by volumeaqueous methanolic solutions were collected and concentrated byevaporation under reduced pressure, and the residue was lyophilized toafford 100 mg of the title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=7.33 Hz); 1.10 (3H, doublet, J=6.23 Hz); 2.20-2.31 (1H,multiplet); 2.87-3.22 (2H, multiplet); 3.10 (3H, singlet); 3.14 (3H,singlet); 3.28 (1H, doublet of doublets, J=6.05 & 2.78 Hz); 3.67-3.73(1H, multiplet); 3.86-4.08 (4H, multiplet); 4.22 (1H, doublet ofdoublets, J=9.35 & 7.50 Hz).

EXAMPLE 2 (1R, 5S, 6S)-2-[(2S,4S)-2-Carbamoyl-1-(2-fluoroethyl)-1-methylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

(1) 10.0 ml of trifluoroacetic acid and 0.25 ml oftrifluoromethanesulfonic acid were added dropwise, whilst ice-cooling,to a suspension of 1.11 g of (2R,4S)-2-carbamoyl-4-(4-methoxybenzylthio)-1-(2-fluoroethyl)-1-methylpyrrolidiniumfluorosulfonate (prepared as described in Preparation 2) in 2.83 ml ofanisole, and the mixture was then stirred at the same temperature for 1hour. At the end of this time, the solvent was distilled off, and theresidue was repeatedly washed by decantation with diethyl ether and thendried under reduced pressure, to afford 927 mg of a (2S,4S)-2-carbamoyl-4-mercapto-1-(2-fluoromethyl)-1-methylpyrrolidiniumsalt.

(2) 0.37 ml of diisopropylethylamine and 0.44 ml of diphenylphosphorylchloride were added dropwise, whilst ice-cooling, to a solution of 720mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxyate in7 ml of dry acetonitrile, and the mixture was stirred at the sametemperature for 1 hour. At the end of this time, 0.88 ml ofdiisopropylethylamine and a solution of the salt prepared as describedin step (1) above in 5 ml of acetonitrile were added dropwise to thereaction mixture, whilst ice-cooling, and then the mixture was allowedto stand for 2 days at the same temperature. The solvent was the removedby distillation under reduced pressure, and the residue was washedrepeatedly by decantation using diethyl ether and then dried underreduced pressure to afford a crude product. This crude product wasdissolved in a mixture of 55 ml of tetrahydrofuran and 55 ml of a 0.1Mphosphate buffer (pH 7.0) and then hydrogenated at room temperature for2 hours in the presence of 1 g of 10% w/w palladium-on-charcoal. At theend of this time, an insoluble material was removed by filtration usinga Celite filter aid, and the filtrate was washed with diethyl ether. Theaqueous layer was concentrated by evaporation under reduced pressure,and the residue was adsorbed on a column of Diaion HP-20AG (MitsubishiChemical Industries, Ltd.). Those fractions eluted with a 5% by volumeaqueous acetone solution were concentrated by evaporation under reducedpressure and lyophilized to afford a crude product as a yellow powder.This crude product was purified by chromatography using Lobar column(Merck Co. LiChroprep RP-8, size B). The fractions eluted with a 2% byvolume aqueous methanolic solution were collected, concentrated byevaporation under reduced pressure and lyophilized to afford 40 mg ofthe title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.03 (3H,doublet, J=7.33 Hz); 1.10 (3H, doublet, J=6.59 Hz); 2.27-2.35 (1H,multiplet); 2.92-3.12 (2H, multiplet); 3.19 (3H, singlet); 3.29 (1H,doublet of doublets, J=6.05 & 2.75 Hz); 3.67-3.78 (2H, multiplet);3.91-4.08 (5H, multiplet); 4.37 (1H, doublet of doublets, J=10.81 & 7.50Hz); 4.69-4.91 (2H, multiplet).

EXAMPLE 3 (1R, 5S, 6S)-2-[(2S,4S)-1,1-Dimethyl-2-methylcarbamoylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

(1) 2.64 ml of trifluoroacetic acid and 0.132 ml oftrifluoromethanesulfonic acid were added dropwise, whilst ice-cooling,to a suspension of 280 mg of (2S,4S)-1,1-dimethyl-2-methylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 3) in 0.744 ml ofanisole, and the mixture was stirred at the same temperature for 2hours. At the end of this time, the solvent was distilled off, and theresidue was washed twice by decantation with diethyl ether and thendried by evaporation under reduced pressure, to afford 230 mg of a crude(2S, 4S)-1,1-dimethyl-2-methylcarbamoyl-4-mercaptopyrrolidinium salt asan oil.

(2) 108 μl of diisopropylethylamine and 129 μl of diphenylphosphorylchloride were added dropwise simultaneously, whilst ice-cooling, to asolution of 225 mg of 4-nitrobenzyl (1R, 5R,6S)-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate in 3ml of dry acetonitrile and the mixture was stirred at the sametemperature for 1 hour. At the end of this time, 118 μl ofdiisopropylethylamine and a solution of the salt prepared as describedin step (1) above in 2 ml of acetonitrile were added the reactionmixture, whilst ice-cooling. The mixture was then allowed to stand at 0°to 5° C. for 2 hours and for 48 hours in a refrigerator. At the end ofthis time, the solvent was distilled off, and the residue was washedrepeatedly by decantation with diethyl ether and dried under reducedpressure to afford a crude product. This crude product was dissolved ina mixture of 20 ml of tetrahydrofuran and 20 ml of a 0.1M phosphatebuffer (pH 7.0) and hydrogenated at room temperature for 2.5 hours inthe presence of 254 mg of 10% w/w palladium-on-charcoal. At the end ofthis time, an insoluble material was removed by filtration using aCelite filter aid, and the filtrate was washed using diethyl ether. Theaqueous layer was concentrated by evaporation under reduced pressure.The resulting residue was adsorbed on a column of Diaion HP-20AG(Mitsubishi Chemical Industries, Ltd.) and the fractions eluted with a5% by volume aqueous acetone solution were concentrated by evaporationunder reduced pressure. The resulting residue was then lyophilized toafford a crude product as a powder. This crude product was purified bychromatography using a Lobar column (Merck Co. LiChroprep RP-8, size B).The fractions eluted with 10% and 15% by volume aqueous methanolicsolutions were collected and concentrated by evaporation under reducedpressure. The resulting residue was lyophilized to afford 9.0 mg of thetitle compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.5.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=7.33 Hz); 1.10 (3H, doublet, J=6.59 Hz); 2.19-2.31 (1H,multiplet); 2.63 (3H, singlet); 2.82-3.23 (2H, multiplet); 3.05 (3H,singlet); 3.12 (3H, singlet); 3.29 (1H, doublet of doublets, J=6.22 &2.93 Hz); 3.70 (1H, doublet of doublets, J=12.46 & 5.13 Hz); 3.83-4.20(5H, multiplet).

EXAMPLE 4 (1R, 5S, 6S)-2-[(2S,4S)-1,1-Dimethyl-2-dimethylcarbamoyl)pyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

(1) 3.3 ml of trifluoroacetic acid and 0.12 ml oftrifluoromethanesulfonic acid were added dropwise, whilst ice-cooling,to a suspension of 350 mg of (2S,4S)-1,1-dimethyl-2-(N,N-dimethylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 4) in 0.669 ml ofanisole, and the mixture was stirred at room temperature for 2 hours. Atthe end of this time, the solvent was removed by distillation underreduced pressure, and the residue was washed twice by decantation withhexane and diethyl ether, in that order, and dried under reducedpressure to afford 316 mg of a crude (2S,4S)-1,1-dimethyl-2-(N,N-dimethylcarbamoyl-4-mercaptopyrrolidinium saltas an oil. This was used in the following reaction without furtherpurification.

(2) 164 μl of diisopropylethylamine and 196 μl of diphenylphosphorylchloride were added simultaneously, whilst ice-cooling, to a solution of326 mg of 4-nitrobenzyl (1R, 5R,6S)-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate in 4ml of dry acetonitrile, and the mixture was stirred at the sametemperature for 1 hour. At the end of this time, 248 μl ofdiisopropylethylamine and a solution of the salt prepared as describedin step (1) above in 3 ml of acetonitrile were added to the reactionmixture, whilst ice-cooling. The mixture was then allowed to stand at 0°to 5° C. for 1 hour and then in a refrigerator for a further 2 days. Atthe end of this time, the reaction mixture was treated in a similarmanner to that described in Example 1-(2). The resulting crude productwas then dissolved in a mixture of 20 ml of tetrahydrofuran and 20 ml ofa 0.1M phosphate buffer (pH 7.0) and hydrogenated at room temperaturefor 2.5 hours in the presence of 400 mg of 10% w/wpalladium-on-charcoal. Reduction and purification were then carried outin a similar manner to that described in Example 1-(2), to afford 101 mgof the title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.03 (3H,doublet, J=7.33 Hz); 1.11 (3H, doublet, J=6.22 Hz); 2.19 (1H, quintet,J=7.20 Hz); 2.83 (3H, singlet); 2.90-3.18 (2H, multiplet); 3.01 (3H,singlet); 3.10 (3H, singlet); 3.12 (3H, singlet); 3.29 (1H, doublet ofdoublets, J=6.23 & 2.56 Hz); 3.74-3.91 (2H, multiplet); 3.96-4.11 (3H,multiplet); 4.76 (1H, triplet, J=7.70 Hz).

EXAMPLE 5 (1R, 5S,6S)-2-[(3S)-1,1-Dimethylpyrrolidinium-3-ylthio]-6-[-(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

(1) 4.97 ml of trifluoroacetic acid and 0.249 ml oftrifluoromethanesulfonic acid were added dropwise, whilst ice-cooling,to a suspension of 453 mg of(3S)-1,1-dimethyl-3-(4-methoxybenzylthio)pyrrolidinium fluorosulfonate(prepared as described in Preparation 5) in 1.40 ml of anisole, and themixture was stirred at the same temperature for 2 hours. At the end ofthis time, the solvent was distilled off, and the residue was washedtwice by decantation with diethyl ether and then dried under reducedpressure, to afford 250 mg of a crude(3S)-1,1-dimethyl-3-mercaptopyrrolidinium salt as an oil.

(2) 126 μl of diisopropylethylamine and 150 μl of diphenylphosphorylchloride were added simultaneously, whilst ice-cooling, to a solution of250 mg of 4-nitrobenzyl (1R, 5R,6S)-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate in 2ml of dry acetonitrile, and the mixture was stirred at the sametemperature for 1 hour. At the end of this time, 145 μl ofdiisopropylethylamine and a solution of the salt prepared as describedin step (1) above in 4 ml of acetonitrile were added the reactionmixture, whilst ice-cooling. The reaction mixture was then allowed tostand at 0° to 5° C. for 2 hours and for 2 days in a refrigerator. Atthe end of this time, the solvent was removed by distillation underreduced pressure, and the residue was mixed with diethyl ether and thendecanted. The resulting crude product was dissolved in a mixture of 20ml of tetrahydrofuran and 20 ml of a 0.1M phosphate buffer (pH 7.0) andhydrogenated at room temperature for 2.5 hours in the presence of 300 mgof 10% w/w palladium-on-charcoal. At the end of this time, an insolublematerial was removed by filtration using Celite filter aid, and thefiltrate was washed using diethyl ether. The aqueous layer wasconcentrated by evaporation under reduced pressure. The residue wasadsorbed on a column of Diaion HP-20AG (Mitsubishi Chemical Industries,Ltd.) and the fractions eluted with a 5% by volume aqueous acetonesolution were concentrated by evaporation under reduced pressure andlyophilized to afford a crude product as a powder. This crude productwas purified by chromatography using a Lobar column (Merck Co.LiChroprep RP-8, size B). The fractions eluted with 10% and 15% byvolume aqueous methanolic solutions were collected, concentrated byevaporation under reduced pressure and lyophilized to afford 9.0 mg ofthe title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.3.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=7.33 Hz); 1.09 (3H, doublet, J=6.59 Hz); 1.96-2.14 (1H,multiplet); 2.52-2.70 (1H, multiplet); 3.00 (3H, singlet); 3.09 (3H,singlet); 3.04-3.18 (1H, multiplet); 3.28 (1H, doublet of doublets,J=6.05 & 2.75Hz), 3.38-3.67 (3H, multiplet); 3.80 (1H, doublet ofdoublets, J=12.46 & 7.70Hz); 3.91-4.11 (3H, multiplet).

EXAMPLE 6 (5R,6S)-2-[(3S)-1,1-Dimethylpyrrolidinium-3-ylthio]-6-[-(1R)-1-hydroxyethyl]-1-carbapen-2-em-3-carboxylate

183 μl of diisopropylethylamine and 218 μl of diphenylphosphorylchloride were simultaneously added, whilst ice-cooling, to a solution of348 mg of 4-nitrobenzyl (5R,6S)-6-[(1R)-1-hydroxyethyl]-2-oxo-1-carbapenam-3-carboxylate dissolvedin 4 ml of dry acetonitrile and the mixture was stirred at the sametemperature for 1 hour. At the end of this time, a solution of 338 mg ofthe crude (3S)-1,1-dimethyl-3-mercaptopyrrolidinium salt prepared asdescribed in Example 5-(1) in 4 ml of dry acetonitrile and 209 μl ofdiisopropylethylamine were added to the mixture, whilst ice-cooling. Themixture was then allowed to stand at the same temperature for 1 hour andthen for two days in a refrigerator. At the end of this time, thereaction mixture was washed by decantation with diethyl ether. Theresulting product was dissolved in a mixture of 30 ml of tetrahydrofuranand 30 ml of a 0.1M phosphate buffer (pH 7.0) and hydrogenated at roomtemperature for 2.5 hours in the presence of 400 mg of 10% w/wpalladium-on-charcoal. At the end of this time, an insoluble materialwas removed by filtration and the filtrate was washed with diethylether. The aqueous layer was concentrated by evaporation under reducedpressure and then subjected to column chromatography through DiaionHP-20AG (Mitsubishi Chemical Industries, Inc.). The title compound wasprepared as a crude product from the fractions eluted with water. Thecrude compound was then further purified by chromatography through aLobar column (Merck Co. LiChroprep RP-8, size B) and the fractionseluted with 5% by volume aqueous methanol were collected, concentratedby evaporation under reduced pressure and lyophilized to afford 60 mg ofthe title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

Nuclear Magnetic Resonance Spectrum (270 MHz, D₂ O) δ ppm: 1.09 (3H,doublet, J=6.23 Hz); 2.01-2.18 (1H, multiplet); 2.53-2.72 (1H,multiplet); 2.89-3.04 (2H, multiplet); 3.01 (3H, singlet); 3.09 (3H,singlet); 3.23 (1H, doublet of doublets, J=6.05 & 2.75 Hz); 3.36-3.67(3H, multiplet); 3.85 (1H, doublet of doublets, J=12.64 & 8.24 Hz),3.93-4.09 (3H, multiplet).

EXAMPLE 7 (1R, 5S,6S)-2-[1,1-Dimethylpiperidinium-4-ylthio]-6-[-(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

7-(1) 31.6 ml of trifluoroacetic acid and 1.6 ml oftrifluoromethanesulfonic acid were added dropwise, whilst ice-cooling,to a suspension of 3.0 g of1,1-dimethyl-4-(4-methoxybenzylthio)piperidinium fluorosulfonate(prepared as described in Preparation 6) in 8.9 ml of anisole. Themixture was stirred for 3 hours, after which it was freed from thesolvent by distillation under reduced pressure. The residue wasrepeatedly washed by decantation with diethyl ether and dried underreduced pressure to afford 2.4 g of a crude1,1-dimethyl-4-mercaptopyrrolidinium salt as an oil.

7-(2) 126 μl of diisopropylethylamine and 150 μl of diphenylsulfonylchloride were added simultaneously, whilst ice-cooling, to a solution of250 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylatedissolved in 2 ml of dry acetonitrile and the mixture was stirred at thesame temperature for 1 hour. At the end of this time, 288 μl ofdiisopropylethylamine and a solution of 245 μl of the salt prepared asdescribed in step (1) in 4 ml of dry acetonitrile were added to themixture, which was then allowed to stand for 2 days in a refrigerator.The reaction mixture was then poured into diethyl ether and theresulting precipitate was washed by decantation. The resulting crudeproduct was then dissolved in 20 ml of a 0.1M phosphate buffer (pH 7.0)and hydrogenated at room temperature for 2 hours in the presence of 331mg of 10% w/w palladium-on-charcoal. At the end of this time, thereaction mixture was worked up in a similar manner to that described inExample 5-(2) to afford 11.3 mg of the title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=6.96 Hz); 1.10 (3H, doublet, J=6.23 Hz); 1.70-1.93 (2H,multiplet); 2.03-2.20 (2H, multiplet); 2.97 (6H, singlet); 3.11-3.48(7H, multiplet); 4.01-4.12 (2H, multiplet).

EXAMPLE 8 (5R,6S)-2-[1,1-Dimethylpiperidinium-4-ylthio]-6-[-(1R)-1-hydroxyethyl]-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 6, but using368 mg of the crude 1,1-dimethyl-4-mercaptopiperidinium salt prepared asdescribed in Example 7-(1) and 363 mg of 4-nitrobenzyl (5R,6S)-6-[(1R)-1-hydroxyethyl]-2-oxo-1-carbapenam-3-carboxylate, 24 mg ofthe title compound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.09 (3H,doublet, J=6.23 Hz); 1.74-1.93 (2H, multiplet); 2.02-2.16 (2H,multiplet); 2.86-3.43 (8H, multiplet); 2.96 (6H, multiplet); 3.97-4.08(2H, multiplet).

EXAMPLE 9 (1R, 5S, 6S)-2-[(2S,4S)-2-(N,N-dimethylcarbamoyl)-1-ethyl-1-methylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

9-(1) 4.94 ml of trifluoroacetic acid and 248 μl oftrifluoromethanesulfonic acid were added, whilst ice-cooling, to asuspension of 560 mg of (2S,4S)-2-(N,N-dimethylcarbamoyl)-1-ethyl-1-methyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 7) in 1.39 ml ofanisole, and the mixture was stirred at the same temperature for 2hours. At the end of this time, the solvent was removed by distillationunder reduced pressure, and the residue was washed twice by decantationwith diethyl ether and then dried under reduced pressure, to afford 460mg of a crude (2S,4S)-2-(N,N-dimethylcarbamoyl)-1-ethyl-1-methyl-4-mercaptopyrrolidiniumsalt as an oil.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.21 (3H,triplet, J=7.33 Hz); 2.14 (1H, doublet of triplets, J=14.29 & 7.15 Hz);2.82 (3H, singlet); 2.98 (3H, singlet); 3.00 (3H, singlet); 2.86-3.94(6H, multiplet); 4.69 (1H, triplet, J=7.15Hz).

9-(2) 152 μl of diisopropylethylamine and 181 μl of diphenylphosphorylchloride were added simultaneously, whilst ice-cooling, to a solution of310 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylatedissolved in 4 ml of dry acetonitrile, and the mixture was stirred for 1hour, whilst ice-cooling. At the end of this time, 174 μl ofdiisopropylethylamine and a solution of 366 mg of the salt prepared asdescribed in step (1) in 4 ml of dry acetonitrile were added to themixture, which was then allowed to stand for 1 hour at 0° to 5° C. andthen for 2 days in a refrigerator. At the end of this time, the reactionmixture was poured into diethyl ether and washed by decantation. Thecrude products thus obtained were dissolved in a mixture of 25 ml oftetrahydrofuran and 25 ml of a 0.1M phosphate buffer (pH 7.0) andhydrogenated at room temperature for 2.5 hours in the presence of 340 mgof 10% w/w palladium-on-charcoal. At the end of this time, the reactionmixture was worked up and purified in a similar manner to that describedin Example 1-(2), to afford 127 mg of the title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.0.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=6.96 Hz); 1.10 (3H, doublet, J=6.22 Hz); 1.22 (3H, triplet,J=7.32 Hz); 2.12-2.25 (1H, multiplet); 2.82 (3H, singlet); 2.83-3.50,(5H, multiplet); 3.00 (3H, singlet); 3.05 (3H, singlet); 3.65 (1H,doublet of doublets, J=12.45 & 5.13 Hz); 3.85 (1H, doublet of doublets,J=12.45 & 8.42 Hz); 3.91-4.12 (3H, multiplet); 4.68-4.75 (1H,multiplet).

EXAMPLE 10 (5R, 6S)-2-[(2S,4S)-1-Ethyl-1-methyl-2-(N,N-dimethylcarbamoyl)pyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 6, but using459 mg of 4-nitrobenzyl (5R,6S)-6-[(1R)-1-hydroxyethyl]-2-oxo-1-carbapenam-3-carboxylate and 580 mgof the crude (2S,4S)-2-(N,N-dimethylcarbamoyl)-1-ethyl-1-methyl-4-mercaptopyrrolidiniumsalt [prepared as described in Example 9-(2)], 55 mg of the titlecompound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.10 (3H,triplet, J=6.59 Hz); 1.23 (3H, triplet, J=7.15 Hz); 2.17-2.30 (1H,multiplet); 2.83 (3H, singlet); 2.83-3.07 (2H, multiplet); 3.00 (3H,singlet); 3.01 (3H, singlet); 3.05 (3H, singlet); 3.24 (1H, doublet ofdoublets, J=6.04 & 2.75 Hz); 3.27-4.18 (7H, multiplet); 4.72 (1H,triplet, J=7.15Hz).

EXAMPLE 11 (5R, 6S)-2-[(2S,4S)-1,1,-Dimethyl-2-(N,N-dimethylcarbamoyl)pyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-carbapen-2-em-3-carboxylate

126 μl of diisopropylethylamine and 132 μl of diphenylphophoryl chloridewere simultaneously added, whilst ice-cooling, to a solution of 218 mgof 4-nitrobenzyl (5R,6S)-6-[(1R)-1-hydroxyethyl]-2-oxo-1-carbapenam-3-carboxylate dissolvedin 3 ml of dry acetonitrile, and the mixture was stirred at the sametemperature for 1 hour. At the end of this time, a solution of 243 mg ofthe crude (2S,4S)-2-(N,N-dimethylcarbamoyl)-1,1-dimethyl-4-mercaptopyrrolidinium salt[prepared as described in Example 4-(1)] in 2 ml of dry acetonitrile and144 μl of diisopropylethylamine were added to the mixture, whilstice-cooling. The mixture was then allowed to stand at the sametemperature for 5 hours and then for 2 days in a refrigerator. At theend of this time, the reaction mixture was worked up in a similar mannerto that described in Example 6. The crude product was dissolved in amixture of 15 ml of tetrahydrofuran and 15 ml of a 0.1M phosphate buffer(pH 7.0) and hydrogenated at room temperature for 2 hours in thepresence of 200 mg of 10% w/w palladium-on-charcoal. At the end of thistime, the reaction mixture was worked up and purified in a similarmanner to that described in Example 6, to afford 56 mg of the titlecompound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 299.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.10 (3H,doublet, J=6.23 Hz); 2.17-2.28 (1H, multiplet); 2.79-3.04 (3H,multiplet); 2.83 (3H, singlet); 3.00 (3H, singlet); 3.11 (3H, singlet);3.12 (3H, singlet); 3.24 (1H, doublet of doublets, J=6.05 & 2.75 Hz);3.76-3.96 (2H, multiplet); 3.97-4.12 (3H, multiplet); 4.76 (1H, triplet,J=7.33Hz).

EXAMPLE 12 (1R, 5S, 6S)-2-[(2S,4S)-1,1-Dimethyl-2-(4-morpholinocarbonyl)pyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 4, but using446 mg of (2S,4S)-1,1-dimethyl-4-(4-methoxybenzylthio)-2-(4-morpholinocarbonyl)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 8) [in step (1)]and 192 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate[in step (2)], 16 mg of the title compound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=7.32 Hz); 1.10 (3H, doublet, J=6.59 Hz); 2.16-2.28 (1H,multiplet); 2.90-3.18 (2H, multiplet); 3.10 (3H, singlet); 3.15 (3H,singlet); 3.29 (1H, doublet of doublets, J=6.23 & 2.93 Hz); 3.43-3.65(8H, multiplet); 3.76-3.93 (2H, multiplet); 3.96-4.12 (3H, multiplet);4.76 (1H, triplet, J=7.69Hz).

EXAMPLE 13 (1R, 5S, 6S)-2-[(2S,4S)-1,1-Dimethyl-2-(1-pyrrolidinocarbonyl)pyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 4, but using472 mg of (2S,4S)-1,1-dimethyl-4-(4-methoxybenzylthio)-2-(1-pyrrolidinocarbonyl)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 9) [in step (1)]and 220 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate[in step (2)], 24 mg of the title compound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=6.96 Hz); 1.10 (3H, doublet, J=6.23 Hz); 1.65-1.84 (4H,multiplet); 2.14-2.24 (1H, multiplet); 2.92-3.04 (1H, multiplet); 3.10(3H, singlet); 3.12 (3H, singlet); 3.20 14 3.57 (5H, multiplet);3.74-4.11 (6H, multiplet); 4.47-4.63 (1H, multiplet).

EXAMPLE 14 (1R, 5S, 6S)-2-[(2S,4S)-2-Carbamoyl-1-ethyl-1-methylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

14-(1) 4.2 ml of trifluoroacetic acid and 0.11 ml oftrifluoromethanesulfonic acid were added dropwise, whilst ice-cooling,to a suspension of 450 mg of (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)-1-ethyl-1-methylpyrrolidiniumfluorosulfonate (prepared as described in Preparation 10) in 1.2 ml ofanisole. The mixture was then stirred at the same temperature for 90minutes, after which it was freed from the solvent by distillation underreduced pressure. The residue was washed by decantation with diethylether and dried under reduced pressure, to afford 370 mg of a (2S,4S)-2-carbamoyl-4-mercapto-1-ethyl-1-methylpyrrolidinium salt as an oil.

Infrared Absorption Spectrum (liquid film) λ_(max) cm⁻¹ : 1699, 1247,1169.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.20 (3H,triplet, J=7.32 Hz); 2.13-2.25 (1H, multiplet); 2.80-3.92 (6H,multiplet); 2.98 (3H, singlet); 4.11-4.17 (1H, multiplet).

14-(2) Following a procedure similar to that described in Example 9, butusing 300 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylateand 340 mg of the salt prepared as described in step (1), 120 mg of thetitle compound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=6.96 Hz); 1.10 (3H, doublet, J=6.23 Hz); 1.23 (3H, triplet,J=7.33 Hz); 2.21-2.35 (1H, multiplet); 2.88-32.5 (2H, multiplet); 3.04(3H, singlet); 3.26-4.08 (8H, multiplet); 4.22 (1H, doublet of doublets,J=10.26 & 7.,32 Hz).

EXAMPLE 15 (5R, 6S)-2-[(2S,4S)-2-Carbamoyl-1-ethyl-1-methylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 11, but using450 mg of 4-nitrobenzyl (5R,6S)-6-[(1R)-1-hydroxyethyl]-2-oxo-1-carbapenam-3-carboxylate and 530 mgof the salt prepared as described in Example 14-(1), 205 mg of the titlecompound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.09 (3H,doublet, J=6.60 Hz); 1.24 (3H, triplet, J=7.33 Hz); 2.26-2.38 (1H,multiplet); 2.84-3.07 (2H, multiplet); 3.03 (3H, singlet); 3.24 (1H,doublet of doublets, J=6.05 & 2.93 Hz); 3.27-4.06 (8H, multiplet); 4.22(1H, doublet of doublets, J=10.26 & 7.33 Hz).

EXAMPLE 16 (5R, 6S)-2-[(2S,4S)-2-Carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-carbapen-2-em-3-carboxylate

210 μl of diisopropylethylamine and 250 μl of diphenylphosphorylchloride were simultaneously added, whilst ice-cooling, to a solution of400 mg of 4-nitrobenzyl (5R,6S)-6-[(1R)-1-hydroxyethyl]-2-oxo-1-carbapenam-3-carboxylate dissolvedin 5 ml of dry acetronitrile, and the mixture was stirred for 1 hour,whilst ice-cooling. At the end of this time, a solution of 447 mg of thecrude (2S, 4S)-2-carbamoyl-1,1-dimethyl-4-mercaptopyrrolidinium saltprepared as described in Example 1-(1) in 5 ml of dry acetonitrile wasadded to the mixture, whilst ice-cooling, and then the mixture wasallowed to stand for 4 hours at the same temperature and then for 2 daysin a refrigerator. The reaction mixture was then poured into diethylether and the resulting deposit was washed repeatedly by decantation.The crude product was dissolved in a mixture of 30 ml of tetrahydrofuranand 30 ml of a 0.1M phosphate buffer (pH 7.0) and hydrogenated at roomtemperature for 2.5 hours in the presence of 450 mg of 10% w/wpalladium-on-charcoal. At the end of this time, insoluble materials wereremoved by filtration using a Celite filter aid. The aqueous layer wasconcentrated by evaporation under reduced pressure, and the residue wastransferred to a column packed with Diaion HP-20AG (Mitsubishi ChemicalsIndustries, Ltd.). Fractions eluted with water were collected andlyophilized to afford the title compound as a powder. This was furtherpurified using a Lobar column (Merck, LiChroprep RP-8 size B) andfractions eluted with a 5% by volume aqueous methanolic solution werecollected and concentrated by evaporation under reduced pressurefollowed by lyophilization, to afford 208 mg of the title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.7.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 Mhz) δ ppm: 1.09 (3H,doublet, J=6.59 Hz); 2.23-2.36 (1H, multiplet); 2.86-3.04 (3H,multiplet); 3.10 (3H, singlet); 3.15 (3H, singlet); 3.23 (1H, doublet ofdoublets, J=5.86 & 2.57 Hz); 3.73 (1H, doublet of doublets, J=12.09 &5.50 Hz); 3.90-4.08 (4H, multiplet); 4.22 (1H, doublet of doublets,J=9.16 & 7.69 Hz.

EXAMPLE 17 (1R, 5S, 6S)-2-[(2S,4S)-2-Ethylcarbamoyl-1-ethyl-1-methylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

17-(1) 10.86 ml of trifluoroacetic acid and 544 μl oftrifluoromethanesulfonic acid were added, whilst ice-cooling, to asuspension of 1.23 g of (2S,4S)-2-ethylcarbamoyl-1-ethyl-1-methyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 11) in 3.06 ml ofanisole, and the mixture was stirred for 2 hours under the sameconditions. The solvent was then removed by distillation under reducedpressure, and the residue was washed thrice by decantation with diethylether and dried under reduced pressure, to afford 0.96 g of a crude (2S,4S)-2-ethylcarbamoyl-1-ethyl-1-methyl-4-mercaptopyrrolidinium salt.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 0.96 (3H,triplet, J=7.33 Hz); 1.21 (3H, triplet, J=7.33 Hz); 2.13-2.26 (1H,multiplet); 2.95 (3H, singlet); 2.73-4.16 (9H, multiplet).

17-(2) Following a procedure similar to that described in Example 1, butusing 250 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylateand 304 mg of the salt prepared as described in step (1), 69 mg of thetitle compound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 296.6.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 0.95 (3H,triplet, J=7.32 Hz); 1.02 (3H, doublet, J=7.33 Hz); 1.10 (3H, doublet,J=6.59 Hz); 1.22 (3H, triplet, J=7.33 Hz); 212-2.34 (1H, multiplet);2.76-2.97 (1H, multiplet); 2.99 (3H, singlet); 3.03-4.18 (12 H,multiplet).

EXAMPLE 18 (5R, 6S)-2-[(2S,4S)-2-ethylcarbamoyl-1-ethyl-1-methylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 16, but using348 mg of 4-nitrobenzyl (5R,6S)-6-[(1R)-1-hydroxyethyl]-2-oxo-1-carbapenam-3carboxylate and 440 mgof the crude (2S,4S)-2-ethylcarbamoyl-1-ethyl-1-methoxy-4-mercaptopyrrolidinium saltprepared as described in Example 17-(1), 80 mg of the title compoundwere obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.2.

Nuclear Magnetic Resonance Spectrum (D₂ O), 270 MHz) δ ppm: 0.95 (3H,triplet, J=7.32 Hz); 1.09 (3H. doublet, J=6.59 Hz); 1.23 (3H, triplet,J=7.33 Hz); 2.13-2.37 (1H, multiplet); 2.76--3.05 (3H, multiplet); 2.98(3H, singlet); 3.09 (2H, quartet, J=7.33 Hz); 3.23 (1H, doublet ofdoublets, J=6.05 & 2.75 Hz); 322-4.18 (8H, multiplet).

EXAMPLE 19 (1R, 5S, 6S)-2-[(2S,4S)-1-Ethyl-1-methyl-2-methylcarbamoylpyrrolidinium-4-ylthio]-6-](1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 1, but using986 mg of (2S,4S)-1-ethyl-1-methyl-2-methylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 12) [in step (1)]and 362 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate[in step (2)], 74 mg of the title compound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 296.6.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=7.33 Hz); 1.10 (3H, doublet, J=6.59 Hz); 1.21 (3H, triplet,J=7.33 Hz); 2.11-2.33 (1H, multiplet); 2.62 (3H, singlet); 2.77--2.90,(1H, multiplet); 2.98 (3H, singlet); 3.00-4.23 (10H, multiplet).

EXAMPLE 20 (1R, 5S, 6S)-2-[(2S,4S)-1,1-Dimethyl-2-ethylcarbamoylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

20-(1) 11.56 of trifluoroacetic acid and 580 μl oftrifluoromethanesulfonic acid were added, whilst ice-cooling, to asuspension of 1.27 g of (2S,4S)-1,1-dimethyl-2-ethylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 13) in 3.26 ml ofanisole, and the mixture was stirred for 2 hours under the sameconditions. At the end of this time, the solvent was removed bydistillation under reduced pressure, and the residue was washed thriceby decantation with diethyl ether and then dried under reduced pressure,to afford 802 mg of a crude (2S,4S)-1,1-dimethyl-2-ethylcarbamoyl-4-mercaptopyrrolidinium salt as anoil.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 0.96 (3H,triplet, J=7.33 Hz); 2.18 (1H, doublet of triplets, J=14.66, 7.33 Hz);2.79-2.98 (1H, multiplet); 3.03 (3H, singlet); 3.06 (3H, singlet); 3.10(2H, quartet, J=7.33 Hz); 3.46-3.92 (3H, multiplet); 4.06 (1H, triplet,J=7.33 Hz).

20-2) 340 mg of diisopropylethylamine and 405 μl of diphenylphosphorylchloride were added simultaneously, whilst ice-cooling, to a solution of674 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylatedissolved in 10 ml of dry acetonitrile, and the mixture was stirred atthe same temperature for 1 hour. At the end of this time, a solution of390 μl of diisopropylethylamine and 790 mg of the salt prepared asdescribed in step (1) in 8 ml of dry acetonitrile were added to thereaction mixture, which was then allowed to stand at 0° to 5° C. for 2hours and then for 2 days in a refrigerator. At the end of this time,the reaction mixture was poured into diethyl ether and washed bydecantation. The resulting crude product was dissolved in a mixture of30 ml of tetrahydrofuran and 30 ml of a 0.1M phosphate buffer (pH 7.0)and hydrogenated at room temperature for 2 hours in the presence of 650mg of 10% w/w palladium-on-charcoal. At the end of this time, thereaction mixture was worked up and purified in a similar manner to thatdescribed in Example 1-(2) to afford 289 mg of the title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.0.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 0.95 (3H,triplet, J=7.15 Hz); 1.02 (3H, doublet, J=7.33 Hz); 1.10 (3H, doublet,J=6.23 Hz); 2.17-2.30 (1H, multiplet); 2.81-3.18 (2H, multiplet); 3.05(3H, singlet); 3.10 (2H, quartet, J=7.33 Hz); 3.11 (3H, singlet); 3.28(1H, doublet of doublets, J=6.05 & 2.76 Hz); 3.69 (1H, doublet ofdoublets, J=12.09 & 5.49 Hz); 3.84-4.16 (5H, multiplet).

EXAMPLE 21 (1R, 5S,6S)-2-[(2S)-1,1-Dimethyl-2-pyrrolidiniummethylthio]6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

21-(1) The procedure described in Example 7-(1) was repeated, but using1.1 g of (2S)-1,1-dimethyl-4-(4-methoxybenzylthiomethyl)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 14), 3.3 ml ofanisole, 11.6 ml of trifluoroacetic acid and 581 ml of trifluorosulfonicacid, to afford 666 mg of a crude(2S)-1,1-dimethyl-4-mercaptomethylpyrrolidinium salt as an oil.

21-(2) 76 μl diisopropylethylamine and 90 μl of diphenylphosphorylchloride were added simultaneously, whilst ice-cooling, to a solution of150 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylatedissolved in 3 ml of dry acetonitrile, and the mixture was stirred atthe same temperature for 1 hour. At the end of this time, 87 μl ofdiisopropylethylamine and a solution of 148 mg of the salt prepared asdescribed in step (1) in 2 ml of dry acetonitrile were added to themixture, whilst ice-cooling, and the mixture was allowed to stand at 0°to 5° C. for 2 hours and then for 1 day in a refrigerator. At the end ofthis time, the reaction mixture was poured into diethyl ether cooled to-78° C. and was washed by decantation. The resulting crude product wasdissolved in a mixture of 13 ml of tetrahydrofuran and 13 ml of a 0.1Mphosphate buffer (pH 7.0) and hydrogenated at room temperature for 2hours in the presence of 210 mg of 10% w/w palladium-on-charcoal.Insoluble materials were removed by filtration with the assistance of aCelite filter aid and the filtrate was concentrated by evaporation underreduced pressure. The residue was subjected to column chromatographythrough CHP-20P (Mitsubishi Chemicals Industries, Ltd.) and fractionseluted with a 5% by volume aqueous acetone solution were collected,concentrated by evaporation under reduced pressure and lyophilized. Theresulting crude product was subjected to column chromatography through acolumn packed with Dowex SOW-X4 (Dow Chemicals Co.) and fractions elutedwith water were collected, concentrated by evaporation under reducedpressure and lyophilized. The resulting crude produce was furtherpurified using a Lobar column RP-8 (Merck) and 45 mg of the titlecompound were obtained from the fractions eluted with a 8% by volumeaqueous methanolic solution.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.04 (3H,doublet, J=7.33 Hz); 1.11 (3H, doublet, J=6.60 Hz); 1.70-2.08 (3H,multiplet); 2.35-2.56 (1H, multiplet); 2.70 (1H, doublet of doublets,J=13.18 & 10.99 Hz); 2.77 (3H, singlet); 3.04 (3H, singlet); 3.08-3.60(6H, multiplet); 4.04-4.09 (2H, multiplet).

EXAMPLE 22 (1R, 5S,6S)-2-[(2R)-1,1-Dimethyl-2-pyrrolidiniummethylthio[-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 21, but using0.94 g of (2R)-1,1-dimethyl-4-(4-methoxybenzylthiomethyl)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 15) [in step (1)]and 470 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenem-3-carboxylate [instep (2)], 70 mg of the title compound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.01 (3H,doublet, J=7.33 Hz); 1.10 (3H, doublet, J=6.23 Hz); 1.69-2.08 (3H,multiplet); 2.28-2.45 (1H, multiplet); 2.79 (3H, singlet); 2.94-3.12(2H, multiplet); 3.07 (3H, singlet); 3.18-3.64 (5H, multiplet);4.01-4.11 (2H, multiplet).

EXAMPLE 23 (1R, 5S, 6S)-2-[(2S,4S)-2-Carbamoyl-1-(2-hydroxyethyl)-1-methylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 7, but using0.37 g of (2S,4S)-2-carbamoyl-1-(2-hydroxyethyl)-4-(4-methoxybenzylthio)-1-methylpyrrolidiniumfluorosufonate (prepared as described in Preparation 16) [in step (1)]and 260 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate[in step (2)], 17 mg of the title compound were obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

EXAMPLE 24 (1R, 5S,6S)-2-(1-Methylquinuclidinium-3-ylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2em-3-carboxylate

24-(1) The procedure described in Example 7-(1) was repeated, but using1.08 g of 3-(4-methoxybenzylthio)-1-methylquinuclidinium fluorosulfonate(prepared as described in Preparation 17), 3.12 ml of anisole, 15 ml oftrifluoroacetic acid and 278 μl of trifluoromethanesulfonic acid, toafford 880 mg of a crude 3-mercapto-1-methylquinuclidinium salt as anoil.

24(2) 135 μl of diisopropylethylamine and 160 μl of diphenylphosphorylchloride were added simultaneously to a solution of 268 mg of4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methoxy-2-oxo-1-carbapenam-3-carboxylatedissolved in 3 ml of dry acetonitrile, and the mixture was stirred atthe same temperature for 1 hour. At the end of this time, 185 μl ofdiisopropylethylamine and a solution of 271 mg of the salt prepared asdescribed in step (1) dissolved in 2 ml of dry acetonitrile were addedto the reaction mixture. The procedure described in Example 21-(2) wasthen repeated, to afford 35 mg of the title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=7.32 Hz); 1.10 (3H, doublet, J=6.6. Hz); 1.66-2.32 (5H,multiplet); 2.80 (3H, singlet); 2.98-3.36 (7H, multiplet); 3.57-3.73(2H, multiplet); 4.00-4.12 (2H, multiplet);

EXAMPLE 25 (1R, 5S, 6S)-2-[(6S,8),-1,4-Dimethyl-5-oxo-4-aza-1-azoniabicyclo[4,3,0]non-8-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-en-3-carboxylate

25-(1) The procedure described in Example 7-(1) was repeated, but using841 mg of (6S,8S)-1,4-dimethyl-8-(4-methoxybenzylthio)-5-oxo-4-aza-1-azoniabicyclo[4.3.0.]nonanefluorosulfonate (prepared as described in Preparation 18), 2.17 ml ofanisole, 7.70 ml of trifluoroacetic acid and 386 μl oftrifluoromethanesulfonic acid, to afford 700 mg of a crude (6S,8S)-1,4-dimethyl-8-mercapto-5-oxo-4-aza-1-azoniabicyclo[4.3.0.]nonanesalt as an oil.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 2.18 (1H,doublet of triplets, J=13.92 & 9.16 Hz); 2.85 (3H, singlet); 2.86-3.04(1H, multiplet); 3.16 (3H, singlet); 3.51-3.90 (6H, multiplet); 3.98(1H, doublet of doublets, J=12.09, 7.69 Hz); 4.26 (1H, triplet, J=8.61Hz).

25-(2) 183 μl of diisopropylethylamine and 218 μl of diphenylphosphorylchloride were added simultaneously, whilst ice-cooling, to a solution of362 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylatedissolved in 5 ml of dry acetonitrile, and the mixture was stirred atthe same temperature for 1 hour. At the end of this time, 209 μl ofdiisopropylethylamine and a solution of 420 mg of the salt prepared asdescribed in step (1) in 3 ml of dry acetonitrile were added to themixture, whilst ice-cooling, and then the procedure described in Example20-(2) was repeated to afford 195 mg of the title compound.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 295.2.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.02 (3H,doublet, J=7.33 Hz); 1.10 (3H, doublet, J=6.59 Hz); 2.23-2.37 (1H,multiplet); 2.86 (3H, singlet); 2.96-3.14 (2H, multiplet); 3.20 (3H,singlet); 3.31 (1H, doublet of doublets, J=5.86, 2.93 Hz); 3.47-3.80(4H, multiplet); 3.83-4.12 (5H, multiplet); 4.34 (1H, triplet, J=7.88Hz).

EXAMPLE 26 (1R, 5S, 6S)-2-[(2RS,4S)-1,1-Dimethyl-2-methoxycarbonylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-en-3-carboxylate

Following a method similar to that described in Example 1, but using(2S,4S)-1,1-dimethyl-4-(4-methoxybenzylthio)-2methoxycarbonylpyrrolidiniumfluorosulfonate (prepared by a similar process to that described inPreparations 1 to 4), the title compound was obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

Nuclear Magnetic Resonance Spectrum (D₂ O), 270 MHz δppm: 1.02, 103,(3H, doublet, J=7.33 Hz); 1.10 (3H, doublet, J=6.23 Hz); 2.27-2.45 (1H,multiplet); 2.83-3.32 (3H, multiplet); 3.01, 3.14 (3H, singlet); 3.19,3.22 (3H, singlet); 3.53-3.77 (1H, multiplet); 3.69 (3H, singlet);3.88-4.12 (4H, multiplet); 4.48 (0.5H, doublet of doublets, J=11.35 &7.69 Hz); 4.65 (0.5H, doublet of doublets, J=10.44 & 8.61 Hz).

EXAMPLE 27 (1R, 5S, 6S)-2-[(2R,4S)-1,1-Dimethyl-2-(N,N-dimethylcarbamoyl)pyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a method similar to that described in Example 4, but using(2R,4S)-1,1-dimethyl-2-(N,N-dimethylcarbamoyl)-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 23), the titlecompound was obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 1.02 (3H,doublet, J=7.33 Hz); 1.10 (3H, doublet, J=6.22 Hz); 2.28-2.41 (1H,multiplet); 2.68-2.80 (1H, multiplet); 2.82 (3H, singlet); 3.01 (3H,singlet); 3.03 (3H, singlet); 3.05-3.16 (1H, multiplet); 3.18 (3H,singlet); 3.29 (1H, doublet of doublets, J=6.23 & 2.94 Hz); 3.50-3.58(1H, multiplet) 4.01-4.18 (4H, multiplet); 4.91 (1H, doublet ofdoublets, J=7.69 & 6.23 Hz).

EXAMPLE 28 (1R, 5S, 6S)-2-[(2R,4S)-2-Carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a method similar to that described in Example 1, but using(2R, 4S)-2-carbamoyl-4-methoxybenzylthio)-1,1-dimethylpyrrolidiniumfluorosulfonate (prepared as described in Preparation 22), the titlecompound was obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 1.03 (3H,doublet, J=6.96 Hz); 1.10 (3H, doublet, J=6.22 Hz); 2.28-2.41 (1H,multiplet); 2.74-2.88 (1H, multiplet); 3.02 (3H, singlet); 3.07-3.18(1H, multiplet); 3.22 (3H, singlet); 3.29 (1H, doublet of doublets,J=6.23 & 2.57 Hz); 3.52-3.63 (1H, multiplet) 3.98-4.17 (4H, multiplet);4.39 (1H, triplet, J=8.06 Hz).

EXAMPLE 29 (1R, 5S, 6S)-2-[(2S,4S)-2-Cyclopropylcarbamoyl-1,1-dimethylpyrrolidinium-4-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a method similar to that described in Example 3, but using(2S,4)-2-cyclopropylcarbamoyl-1,1-dimethyl-4(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate (prepared as described in Preparation 24), the titlecompound was obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 0.37-0.42 (2H,multiplet); 0.59-0.64 (2H, multiplet); 1.01 (3H, doublet, J=7.32 Hz);1.09 (3H, doublet, J=6.32 Hz); 2.17-2.29 (1H, multiplet); 2.47-2.55 (1H,multiplet); 2.80-3.13 (2H, multiplet); 3.05 (3H, singlet); 3.09 (3H,singlet); 3.28 (1H, doublet of doublets, J=6.05 & 2.75 Hz); 3.69 (1H,doublet of doublets, J=12.09 & 6.05 Hz); 3.84-4.10 (5H, multiplet).

EXAMPLE 30 (1R, 5S,6S)-2-(1,1-Dimethylazetidinium-3-ylthio]-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a method similar to that described in Example 5, but using1,1-dimethyl-4-(4-methoxybenzylthio)azetidinium fluorosulfonate, thetitle compound was obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 297.

EXAMPLE 31 (1R, 5S,6S)-2-(4,4-Dimethylmorpholinium-2-ylmethylthio)-6[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a method similar to that described in Example 5, but using4,4-dimethyl-2-(4-methoxybenzylthio]methylmorpholinium fluorosulfonate,the title compound was obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 298.

EXAMPLE 32 (1R, 5S, 6S)-2-[(6S,8S)-5-Oxo-1-methyl-4-aza-1-azoniabicyclo[4.3.0]non-8-ylthio]-6-](1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-en-3-carboxylate

Following a method similar to that described in Example 25, but using(6S,8S)-5-oxo-8-(4-methoxybenzylthio)-1-methyl-4-aza-1-azoniabicyclo[4.3.0]nonanefluorosulfate (prepared as described in Preparation 25), the titlecompound was obtained.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 296.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 1.02 (3H,doublet, J=7.33 Hz); 1.09 (3H, doublet, J=6.23 Hz); 2.23-2.37 (1H,multiplet); 2.95-3.27 (2H, multiplet); 3.19 (3H, singlet); 3.30 (1H,doublet of doublets, J=6.23 & 2.94 Hz); 3.45-3.93 (5H, multiplet);3.96-4.13 (4H, multiplet); 4.32 (1H, triplet, J=8.245 Hz).

EXAMPLE 33 Sodium (1R, 5S,6S)-2-(2-oxo-3-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

126 μl of diisopropylethylamine and 150 μl of diphenylphosphorylchloride were added, whilst stirring and ice-cooling, to a solution of250 mg of 4-nitrobenzyl (1R, 5R,6S)-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate in 3ml of dry acetonitrile, and then the mixture was stirred at 0°-5° C. for1 hour. At the end of this time, 288 μl of diisopropylethylamine and asolution of 222 mg of a 1:1 by weight mixture of3-mercapto-2-pyrrolidinone (prepared by a similar process to thatdescribed in Preparation 19) and trifluoromethanesulfonic acid in 2 mlof acetonitrile were added, with ice-cooling, to the previous reactionmixture. The whole mixture was then allowed to stand for 3 days in arefrigerator. At the end of this time, the mixture was diluted withethyl acetate, washed, in turn, with an aqueous solution of sodiumbicarbonate and an aqueous solution of sodium chloride, and then driedover anhydrous magnesium sulfate. The solvent was then distilled offunder reduced pressure to leave a crude product, which was dissolved ina mixture of 20 ml of tetrahydrofuran and 20 ml of a 0.1M phosphatebuffer solution (pH 7.1), and then hydrogenated at room temperature for2 hours in the presence of 331 mg of 10% w/w palladium-on-charcoal. Atthe end of this period, insoluble matter was removed by filtration usinga Celite filter aid and the filtrate was washed with diethyl ether. Theaqueous phase was concentrated by evaporation under reduced pressure,and the residue was subjected to column chromatography through DiaionHP-20AG, eluted with water. The eluate was concentrated by evaporationunder reduced pressure and then lyophilized to give a crude product.This was further purified by Lobar column chromatography (Merck,LiChroprep RP-8, size B), eluted with a 3% by volume aqueous methanolsolution. The eluate was concentrated by evaporation under reducedpressure and lyophilized to give 35 mg of the title compound in the formof a colorless powder.

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 302.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 1.00 (3H,doublet, J=7.33 Hz); 1.11 (3H, doublet, J=6.60 Hz); 1.86-1.98 (1H,multiplet); 2.40-2.55 (1H, multiplet); 3.18-3.39 (4H, multiplet); 3.71(1H, doublet of doublets, J=9.16 & 6.60 Hz); 4.02-4.12 (2H, multiplet).

EXAMPLE 34 Sodium (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methylcarbapen-2-em-3-carboxylate

126 μl of diisopropylethylamine and 150 μl of diphenylphosphorylchloride were added, whilst stirring and ice-cooling, to a solution of250 mg of 4-nitrobenzyl (1R, 5R,6S)-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate in 5ml of dry acetonitrile, and then the mixture was stirred at 0°-5° C. for1 hour. At the end of this time, 144 μl of diisopropylethylamine and 97mg of 4-mercapto-2-pyrrolidinone (prepared as described in Preparation20) were added, with ice-cooling, to the previous reaction mixture. Thewhole mixture was then stirred at 0°-5° C. for 7 hours and then allowedto stand overnight in a refrigerator. At the end of this time, themixture was diluted with ethyl acetate, washed twice with an aqueoussolution of sodium chloride, and then dried over anhydrous magnesiumsulfate. The solvent was then distilled off under reduced pressure toleave a crude product, which was dissolved in a mixture of 20 ml oftetrahydrofuran and 20 ml of a 0.1 M phosphate buffer solution (pH 7.1),and then hydrogenated at room temperature for 2.5 hours in the presenceof 331 mg of 10% w/w palladium-on-charcoal. At the end of this time,insoluble matter was removed by filtration using a Celite filter aid andthe filtrate was washed with diethyl ether. The aqueous phase wasconcentrated by evaporation under reduced pressure, and the residue wassubjected to column chromatography through Diaion HP-20AG, eluted withwater. The eluate was concentrated by evaporation under reduced pressureand then lyophilized to give a crude product. This was further purifiedby Lobar column chromatography (Merck, LiChroprep RP-8, size B), elutedwith a 3% by volume aqueous methanol solution. The eluate wasconcentrated by evaporation under reduced pressure and lyophilized togive 91 mg of the title compound in the form of a colorless powder. Thisis a mixture of the two isomers in respect of the carbon atom at the4-position of the pyrrolidine ring, in proportions of about 1:1."

Ultraviolet Absorption Spectrum (H₂ O) λ_(max) nm: 300.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 1.02 & 1.03(3H, doublet x 2, J=7.33 & 6.96 Hz); 1.10 (3H, doublet, J=6.60 Hz); 2.12& 2.22 (1H, doublet of doublets x 2, J=17.59 & 4.40 Hz and 17.59 & 4.03Hz); 2.74 & 2.77 (1H, doublet of doublets x 2, J=17.59 & 9.16 Hz and17.59 & 9.16 Hz); 3.07-3.29 (3H, multiplet); 3.64-3.73 (1H, multiplet);3.84-3.96 (1H, multiplet); 4.00-4.12 (2H, multiplet).

EXAMPLE 35 5-Methyl-2-oxo-1,3-dioxolen-4-ylmethyl (1R, 5S,6S)-2-(2-oxo-3-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

A solution of 66 mg of 5-methyl-2-oxo-1,3-dioxolen-4-ylmethyl iodide(prepared by heating 5-methyl-2-oxo-1,3-dioxolen-4-ylmethyl bromide andsodium iodide under reflux in acetone) in chloroform was added to amixture of 47.6 mg of sodium (1R, 5S,6S)-2-(2-oxo-3-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateand 0.4 ml of dry dimethylformamide. The mixture was stirred at roomtemperature for 80 minutes and then at 30°-45° C. for 4.5 hours. At theend of this time, the reaction mixture was diluted with ethyl acetateand washed four times with an aqueous solution of sodium chloride. Theextract was dried and the solvent was distilled off under reducedpressure. The residue was purified by Lobar column chromatography(Merck, LiChroprep Si60, size A), eluted with a 10:1 by volume mixtureof ethyl acetate and methanol, to give 27.4 mg of the title compound inthe form of a colorless powder.

Ultraviolet Absorption Spectrum (CH₃ OH) λ_(max) nm: 322.

Nuclear Magnetic Resonance Spectrum (hexadeuterated dimethyl sulfoxide,270 MHz) δppm: 1.13 (3H, doublet, J=7.32 Hz); 1.15 (3H, doublet, J=6.35Hz); 1.84-1.98 (1H, multiplet); 2.17 (3H, singlet); 2.50-2.65 (1H,multiplet); 3.12-3.45 (4H, multiplet); 3.77-4.06 (2H, multiplet); 4.14(1H, doublet of doublets, J=9.27 & 2.44 Hz); 5.08 (2H, singlet).

EXAMPLE 36 Sodium (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

1.45 ml of diisopropylethylamine and 1.70 ml of diphenylphosphorylchloride were added, whilst ice-cooling, to a solution of 2.93 g of4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate in50 ml of dry acetonitrile, and then the mixture was stirred at 0°-5° C.for 30 minutes. 1.45 ml of diisopropylethylamine and a solution of 1.35g of 4-mercapto-2-pyrrolidinone (prepared as described in Preparation20) in 5 ml of acetonitrile were added to the mixture, cooled at -20°C., and then the whole mixture was stirred at 0° C. for 3 hours, afterwhich it was allowed to stand at the same temperature overnight. Thereaction mixture was then diluted with ethyl acetate, washed twice withan aqueous solution of sodium chloride and filtered. The organic phasewas dried over anhydrous sodium sulfate and the solvent was distilledoff under reduced pressure to give the 4-nitrobenzyl ester of the titlecompound as a foam. This was dissolved in 150 ml of tetrahydrofuran andthe solution was filtered to remove insoluble matter. 150 ml of a 0.1 Mphosphate buffer solution (pH 7.1) were added to the filtrate andcatalytic reduction was effected at room temperature for 2.5 hours inthe presence of 1.5 g of 10% w/w palladium-on-charcoal. The reactionmixture was then worked up in a similar manner to that described inExample 34, to give 1.05 g of the title compound as a colorless powder.This is a mixture of the two isomers in respect of the carbon atom atthe 4-position of the pyrrolidine ring, in proportions of about 9:1.

Ultraviolet Absorption Spectrum (H₂) λ_(max) nm: 299.

Infrared Absorption Spectrum (KBr) σ_(max) cm⁻¹ : 1748, 1689, 1597,1393, 1296.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 1.03 (3H,doublet, J=7.3 Hz); 1.10 (3H, doublet, J=6.2 Hz); 2.12 (0.9 H, doubletof doublets, J=17.9 & 4.4 Hz); 2.22 (0.1 H, doublet of doublets, J=17.9& 4.4 Hz); 2.74, 2.77 (1H, 2×doublet of doublets, J=17.9 & 8.4 Hz);3.08-3.24 (2H, multiplet); 3.26 (1H, doublet of doublets, J=5.9 & 2.6Hz); 3.69 (1H, doublet of doublets, J=11.4 & 6.6 Hz); 3.84-3.93 (1H,multiplet); 4.02-4.11 (2H, multiplet).

EXAMPLE 37 Sodium (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

A crude p-nitrobenzyl ester of the title compound was prepared,following substantially the same procedure as described in Example 36above but using 330 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]- 1-methyl-2-oxo-1-carbapenam-3-carboxylate.The ester was subjected to column chromatography through 50 g of silicagel, eluted with a 4:1 by volume mixture of ethyl acetate and methanol.The eluent was concentrated by evaporation under reduced pressure togive 260 mg of a colorless powder, which was mixed with 10 ml of ethylacetate. This mixture was ice-cooled and filtered to remove insolublematter. The filtrate was concentrated by evaporation under reducedpressure, and diisopropyl ether was added to the residue to give aprecipitate. This was collected by filtration and dried to give 150 mgof the p-nitrobenzyl ester of the title compound as a powder which iseither the R- or the S-isomer in respect of the carbon atom at the4-position of the pyrrolidine ring.

Nuclear Magnetic Resonance Spectrum (hexadeuterated dimethyl sulfoxide,270 MHz) δppm: 1.16 (3H, doublet, J=6.0 Hz); 1.18 (3H, doublet, J=7.3Hz); 2.02 (1H, doublet of doublets, J=17.1 & 4.9 Hz); 2.72 (1H, doubletof doublets, J=17.1 & 8.3 Hz); 3.12-3.48 (3H, multiplet); 3.74 (1H,doublet of doublets, J=10.7 & 6.3 Hz); 3.94-4.05 (2H, multiplet); 4.24(1H, doublet of doublets, J=9.8 & 2.9 Hz); 5.06 (1H, doublet, J=4.9 Hz);5.30, 5.46 (2H, AB, J=14.2 Hz); 7.71 (2H, doublet, J=8.8 Hz); 8.23 (2H,doublet, J=8.8 Hz).

100 mg of the p-nitrobenzyl ester obtained in the previous step weresubjected to catalytic hydrogenation in a similar manner to thatdescribed in Example 34, to give 55 mg of the title compound havingeither the R- or the S-configuration, in respect of the carbon atom atthe 4-position of the pyrrolidine ring, in a pure state as a powder.

Ultraviolet Absorption Spectrum λ_(max) nm: 299 (H₂ O).

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 1.03 (3H,doublet, J=7.3 Hz); 1.10 (3H, doublet, J=6.2 Hz); 2.12 (1H, doublet ofdoublets, J=17.9 & 4.4 Hz); 2.74 (1H, doublet of doublets, J=17.9 & 8.4Hz); 3.08-3.24 (2H, multiplet); 3.26 (1H, doublet of doublets, J=5.9 &2.6 Hz); 3.69 (1H, doublet of doublets, J=11.4 & 6.6 Hz); 3.84-3.93 (1H,multiplet); 4.02-4.11 (2H, multiplet).

EXAMPLE 38 Sodium (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

A crude p-nitrobenzyl ester of the title compound was prepared,following substantially the same procedure as that described in Example34, but using 300 mg of 4-nitrobenzyl (1R, 5R,6S)-6-[(1R)-1-hydroxyethyl]-1-methyl-2-oxo-1-carbapenam-3-carboxylate.The ester was subjected to column chromatography through 50 g of silicagel, eluted with a 4:1 by volume mixture of ethyl acetate and methanol.The eluent was concentrated by evaporation under reduced pressure togive 270 mg of a colorless powder. The product is about a 1:1 mixture ofthe two isomers in respect of the carbon atom at the 4-position of thepyrrolidine ring. 100 mg of this product were mixed with 10 ml of ethylacetate. The mixture was filtered to collect the insoluble matter, whichwas recrystallized from a mixture of methanol and ispropanol to give 30mg of the p-nitrobenzyl ester of the title compound as colorlessneedles. This is either the R- or the S-isomer in respect of the carbonatom at the 4-position of the pyrrolidine ring and is the other isomerhaving the opposite configuration of the compound obtained in the firststep of Example 37.

Nuclear Magnetic Resonance Spectrum (hexadeuterated dimethyl sulfoxide,270 MHz) δppm: 1.16 (3H, doublet, J=6.3 Hz); 1.17 (3H, doublet, J=7.3Hz); 2.13 (1H, doublet of doublets, J=17.1 & 4.4 Hz); 2.79 (1H, doubletof doublets, J=17.1 & 7.8 Hz); 3.10 (1H, doublet of doublets, J=10.8,3.4 Hz); 3.16-3.35 (1H, multiplet); 3.40-3.51 (1H, multiplet); 3.70 (1H,doublet of doublets, J=10.7 & 7.3 Hz); 3.95-4.12 (2H, multiplet); 4.25(1H, doublet of doublets, J=9.3 & 2.5 Hz); 5.07 (1H, doublet, J=5.4 Hz);5.30, 5.46 (2H, AB, J=14.2 Hz); 7.71 (2H, doublet, J=8.8 Hz); 8.23 (2H,doublet, J=8.8 Hz).

20 mg of the p-nitrobenzyl ester obtained in the previous step weresubjected to catalytic hydrogenation in a similar manner to thatdescribed in Example 34, to give 11 mg of the title compound havingeither the R- or the S-configuration, in respect of the carbon atom atthe 4-position of the pyrrolidine ring and having the oppositeconfiguration to that obtained in Example 37, in a pure state as apowder.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 1.02 (3H,doublet, J=7.3 Hz); 1.10 (3H, doublet, J=6.6 Hz); 2.22 (1H, doublet ofdoublets, J=17.6 & 4.4 Hz); 2.77 (1H, doublet of doublets, J=17.6 & 8.4Hz); 3.08-3.25 (2H, multiplet); 3.25 (1H, doublet of doublets, J=5.9 &2.6 Hz); 3.68 (1H, doublet of doublets, J=11.4 & 6.4 Hz); 3.84-3.96 (1H,multiplet); 4.00-4.12 (2H, multiplet).

EXAMPLE 39 Pivaloyloxymethyl (1R, 5S, 6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

100 mg of sodium2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateobtained by a similar procedure to that described in Example 36 weresuspended in 3 ml of dry N,N-dimethylacetamide. 80 μl ofpivaloyloxymethyl iodide were added, whilst ice-cooling, to thesuspension, and then the mixture was stirred for 15 minutes, duringwhich time the mixture became a solution. The reaction mixture was thendiluted with 50 ml of ethyl acetate and washed twice with an aqueoussolution of sodium chloride. The organic phase was dried over anhydroussodium sulfate and the solvent was distilled off under reduced pressure.The residue was purified by Lobar column chromatography (Merck,LiChroprep RP-8, size B), eluted with 60% by volume aqueous methanol.The eluent was evaporated under reduced pressure to remove the methanol,leaving the aqueous phase, which was mixed with sodium chloride and thenextracted with ethyl acetate. The extract was dried over anhydroussodium sulfate and concentrated by evaporation under reduced pressure togive 110 mg of the title compound as a colorless powder.

Ultraviolet Absorption Spectrum (CH₃ CN) λ_(max) nm: 3.23 (ε=10760).

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1778, 1756, 1699.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δppm: 1.23 (9H,singlet); 1.29 (3H, doublet, J=7.3 Hz); 1.35 (3H, doublet of doublets,J=6.2 Hz); 1.95 (1H, broad singlet); 2.33 (1H, doublet of doublets,J=17.6 & 6.2 Hz); 2.79 (1H, doublet of doublets, J=17.6 & 8.8 Hz);3.22-3.34 (2H, multiplet); 3.38 (1H, doublet of doublets, J=9.9 & 4.8Hz); 3.80 (1H, doublet of doublets, J=10.3 & 7.0 Hz); 3.95-4.05 (1H,multiplet); 4.20-4.27 (2H, multiplet); 5.79 (1H, broad singlet); 5.83,5.97 (2H, AB, J=5.5 Hz).

EXAMPLE 40 (1-Methylcyclohexan-1-yl)carbonyloxymethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a similar procedure to that described in Example 39, but using(1-methylcyclohexan-1-yl)carbonyloxymethyl iodide in place ofpivaloyloxymethyl iodide, the title compound was obtained.

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23 (ε=9655).

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1777, 1753, 1700.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δppm: 1.18 (3H,singlet); 1.29 (3H, doublet, J=7.3 Hz); 1.35 (3H, doublet, J=6.2 Hz);1.25-1.75 (9H, multiplet); 2.00-2.08 (2H, multiplet); 2.33 (1H, doubletof doublets, J=17.6 & 6.2 Hz); 2.79 (1H, doublet of doublets, J=17.6 &8.8 Hz); 3.21-3.33 (2H, multiplet); 3.38 (1H, doublet of doublets, J=9.0& 4.8 Hz); 3.79 (1H, doublet of doublets, J=9.0 & 7.0 Hz); 3.95-4.05(1H, multiplet); 4.21-4.30 (2H, multiplet); 5.78 (1H, broad singlet);5.87, 5.96 (2H, AB, J=5.5 Hz).

EXAMPLE 41 1-(Cyclohexyloxycarbonyloxy)ethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 39, but using54 mg of sodium2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateobtained by a similar procedure to that described in Example 36 and 50μl of 1-(cyclohexyloxycarbonyloxy)ethyl iodide, 62 mg of the titlecompound were obtained as a colorless powder.

Ultraviolet Absorption Spectrum (CH₃ CN) λ_(max) nm: 323 (ε=10766).

Infrared Absorption Spectrum (KBR) ν_(max) cm⁻¹ : 1759, 1701.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δppm: 1.28 (3H,doublet, J=7.0 Hz); 1.33, 1.36 (3H, two doublets, J=6.2 Hz); 1.59, 1.61(3H, two doublets, J=5.5 Hz); 1.2-1.6 (6H, multiplet); 1.7-2.0 (5H,multiplet); 2.33 (1H, doublet of doublets, J=17.6 & 6.2 Hz); 2.79 (1H,doublet of doublets, J=17.6 & 8.8 Hz); 3.24-3.33 (2H, multiplet);3.35-3.42 (1H, multiplet); 3.76-3.85 (1H, multiplet); 3.94-4.05 (1H,multiplet); 4.19-4.27 (2H, multiplet); 4.59-4.70 (1H, multiplet); 5.69(1H, broad singlet); 6.88 (1H, quartet, J=5.5 Hz).

EXAMPLE 42 1-(Cyclopentyloxycarbonyloxy)ethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 39, but using1-(cyclopentyloxycarbonyloxy)ethyl iodide, the title compound wasobtained.

Ultraviolet Absorption Spectrum (CH₃ CN) λ_(max) nm: 322 (ε=10651).

Infrared Absorption Spectrum (KRb) ν_(max) cm⁻¹ : 1760, 1701.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δppm: 1.28, 1.29(3H, two doublets, J=7.3 Hz); 1.33, 1.35 (3H, two doublets, J=6.2 Hz);1.58, 1.60 (3H, two doublets, J=5.5 Hz); 1.65-1.95 (8H, multiplet); 2.33(1H, doublet of doublets, J=17.6 & 6.2 Hz); 2.79 (1H, doublet ofdoublets, J=17.6 & 8.8 Hz); 3.23-3.32 (2H, multiplet); 3.38, 3.39 (1H,two doublet of doublets, J=9.9 & 4.8 Hz); 3.68-3.87 (1H, multiplet);3.96-4.07 (1H, multiplet); 4.19-4.27 (2H, multiplet); 5.08-5.16 (1H,multiplet); 5.66 (1H, broad singlet); 6.87 (1H, quartet, J=5.5 Hz).

EXAMPLE 43 1-(Cyclohexylmethyloxycarbonyloxy)ethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 39, but using1-(cyclohexylmethyloxycarbonyloxy)ethyl iodide, the title compound wasobtained.

Ultraviolet Absorption Spectrum (CH₃ CN) λ_(max) nm: 3.23 (ε=10975).

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1766, 1700, 1269.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δppm: 0.95-1.26(5H, multiplet); 1.28, 1.29 (3H, two doublets, J=7.3 Hz); 1.33, 1.35(3H:, two doublets, J=6.2 Hz); 1.59, 1.61 (3H, two doublets, J=5.9 & 5.5Hz); 1.64-1.76 (6H, multiplet); 1.87 (1H, broad singlet); 2.33 (1H,doublet of doublets, J=17.6 & 6.2 Hz); 2.79 (1H, doublet of doublets,J=17.6 & 8.8 Hz); 3.24-3.35 (2H, multiplet); 3.37-3.42 (1H, multiplet);3.75-3.87 (1H, multiplet); 3.95-4.06 (3H, multiplet); 4.20-4.28 (2H,multiplet); 5.73 (1H, broad singlet); 6.86, 6.87 (1H, two quartets,J=5.9 & 5.5 Hz).

EXAMPLE 44 1-(Isopropoxycarbonyloxy)ethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 39, but using1-(isopropoxycarbonyloxy)ethyl iodide, the title compound was obtained.

Ultraviolet Absorption Spectrum (CH₃ CN) λ_(max) nm: 3.23 (ε=10961).

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1762, 1701, 1272.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δppm: 1.26-1.36(12H, multiplet); 1.59, 1.61 (3H, two doublets, J=5.5 Hz); 1.80 (1H,broad triplet, J=3.7 Hz); 2.33 (1H, doublet of doublets, J=17.6 & 6.2Hz); 2.79 (1H, doublet of doublets, J=17.6 & 8.8 Hz); 3.24-3.34 (2H,multiplet); 3.35-3.42 (1H, multiplet); 3.76-3.87 (1H, multiplet);3.95-4.07 (1H, multiplet); 4.19-4.28 (2H, multiplet); 4.82-4.99 (1H,multiplet); 5.63 (1H, broad singlet); 6.88 (1H, quartet, J=5.5 Hz).

EXAMPLE 45 (1R, 2S, 5R)-(l)-Menthyloxycarbonyloxymethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 39, but using(1R, 2S, 5R)-(l)-menthyloxycarbonyloxymethyl iodide, the title compoundwas obtained.

Ultraviolet Absorption Spectrum (CH₃ CN) λ_(max) nm: 3.24 (ε=10801).

Infrared Absorption spectrum (KBr) ν_(max) cm⁻¹ : 1763, 1695, 1266.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δppm: 0.78 (3H,doublet, J=7.0 Hz); 0.89 (3H, doublet, J=7.0 Hz); 0.92 (3H, doublet,J=7.3 Hz); 1.29 (3H, doublet, J=7.3 Hz); 1.35 (3H, doublet, J=6.2 Hz);0.95-1.55 (5H, multiplet); 1.63-1.73 (2H, multiplet); 1.88-2.03 (1H,multiplet); 2.08-2.17 (1H, multiplet) 2.34 (1H, doublet of doublets,J=17.2 & 6.2 Hz); 2.79 (1H, doublet of doublets, J=17.2 & 8.8 Hz);3.22-3.34 (2H, multiplet); 3.39 (1H, doublet of doublets, J=9.5 & 4.8Hz); 3.74-3.86 (1H, multiplet); 3.96-4.06 (1H, multiplet); 4.18-4.28(2H, multiplet); 4.56 (1H, doublet of triplets, J=10.6 & 4.4 Hz); 5.70(1H, broad singlet); 5.89, 5.91 (2H, AB, J=5.9 Hz).

EXAMPLE 46 5-Methyl-2-oxo-1,3-dioxolen-4-ylmethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Following a procedure similar to that described in Example 39, but using50 mg of sodium2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylateand 55 mg of 5-methyl-2-oxo-1,3-dioxolen-4-ylmethyl bromide, 50 mg ofthe title compound were obtained as a colorless powder.

Ultraviolet Absorption Spectrum (CH₃ CN) λ_(max) nm: 321.1 (ε=8982).

Infrared Absorption Spectrum (CHCl₃) ν_(max) cm⁻¹ : 1820, 1772, 1701,1627.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δppm: 1.30 (3H,doublet, J=7.33 Hz); 1.36 (3H, doublet, J=6.22 Hz); 1.80 (1H, broadsinglet); 2.21 (3H, singlet); 2.35 (1H, doublet of doublets, J=17.58 &6.04 Hz); 2.81 (1H, doublet of doublets, J=17.58 & 8.80 Hz); 3.25-3.43(3H, multiplet); 3.73-4.05 (2H, multiplet); 4.17-4.32 (2H, multiplet);4.96, 5.05 (2H, AB, J=13.93 Hz); 5.59 (1H, broad singlet).

EXAMPLES 47 TO 56 Example 47 1-(Isobutyryloxy)ethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23.

Example 48 1-(Cyclohexanecarbonyloxy)ethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23.

Example 49 1-(Pivaloyloxy)ethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23.

Example 50 1-Acetoxyethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23.

Example 51 Cycohexanecarbonyloxymethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23.

Example 52 Cyclohexyloxycarbonyloxymethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23.

Example 53 Cyclopentyloxycarbonyloxymethyl (1R, 5S,6S)-2-(2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23.

Example 54 Sodium (1R, 5S,6S)-2-(1-methyl-2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.00.

Example 55 Pivaloyloxymethyl (1R, 5S,6S)-2-(1-methyl-2-oxo-4-pyrrolidinylthio)-6-[(1R)-12-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23.

Example 56 1-(Isopropoxycarbonyloxy)ethyl (1R, 5S,6S)-2-(1-methyl-2-oxo-4-pyrrolidinylthio)-6-[(1R)-1-hydroxyethyl]-1-methyl-1-carbapen-2-em-3-carboxylate

Ultraviolet Absorption spectrum (CH₃ CN) λ_(max) nm: 3.23.

Preparation 1 (2S,4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-1,1-dimethylpyrrolidiniumfluorosulfonate 1-(1) (2S,4R)-1-t-Butoxycarbonyl-4-hydroxy-2-pyrrolidinecarboxylic acid

27.3 g of sodium hydroxide were dissolved in 280 ml of water, and 85 gof (2S, 4R)-4-hydroxy-2-pyrrolidinecarboxylic acid were then added tothe solution at 3° to 5° C. followed by 570 ml of tetrahydrofuran at thesame temperature. A solution of 141.5 g of di-t-butoxy carbonate in 190ml of tetrahydrofuran was then added to the reaction mixture at 3° to 5°C., and then the mixture was stirred at 50° to 55° C. for 2 hours. Atthe end of this time, the mixture was cooled, and then its pH wasadjusted to a value of 3 to 4 by the addition of concentratedhydrochloric acid followed by ammonium chloride. The mixture was thenextracted with tetrahydrofuran and the extract was dried. The solventwas then distilled from the extract under reduced pressure, giving 128 gof the title compound as a colorless powder.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δppm: 1.44 (9H,singlet); 1.96-2.45 (2H, multiplet); 2.36-2.72 (2H, multiplet);4.24-4.66 (2H, multiplet); 5.04-5.60 (2H, multiplet).

1-(2) (2S, 4R)-1-t-Butoxycarbonyl-2-carbamoyl-4-hydroxypyrrolidine

58 g of (2S, 4R)-1-(t-butoxycarbonyl)-4-hydroxy-2-pyrrolidinecarboxylicacid [prepared as described in step (1) aboveπ were dissolved in 850 mlof dry tetrahydrofuran, and then 38.2 ml of triethylamine were added tothe mixture at -15° to -20° C. A solution of 26.3 ml of ethylchloroformate in 240 ml of dry tetrahydrofuran was then added dropwiseto the mixture at -15° to -20° C., and the mixture was stirred at thesame temperature for 35 minutes. At the end of this time, 258 ml of 28%w/v aqueous ammonium hydroxide were added to the mixture at -15° to -20°C., and the mixture was allowed to stand overnight at room temperature.Ammonium chloride was then added to the reaction mixture, which was thenextracted with tetrahydrofuran. The extract was dried and freed from thesolvent by distillation under reduced pressure. The resulting residuewas triturated with diethyl ether to cause crystallization. The crystalswere collected by filtration and washed with diethyl ether to afford49.7 g of the title compound as colorless crystals, melting at 146°-148°C.

Nuclear Magnetic Resonance Spectrum (hexadeuterated dimethyl sulfoxide,60 MHz) δppm: 1.38 (9H, singlet); 1.65-2.24 (2H, multiplet); 3.00-3.66(2H, multiplet); 3.76-4.49 (3H, multiplet); 6.78 (1H, broad singlet);7.23 (1H, broad singlet).

1-(3) (2S,4R)-1-(t-Butoxycarbonyl)-2-carbamoyl-4-methanesulfonyloxypyrrolidine

1.85 ml of methanesulfonyl chloride was added, whilst ice-cooling, to asolution of 5.0 g of (2S,4R)-1-(t-butoxycarbonyl)-2-carbamoyl-4-hydroxypyrrolidine [prepared asdescribed in step (2) above] in 250 ml of dry tetrahydrofuran, followedby 3.31 ml of triethylamine. The mixture was then stirred at 0° to 5° C.for 1 hour, after which it was poured into an aqueous solution of sodiumchloride and extracted with ethyl acetate. The extract was washed withan aqueous solution of sodium chloride and dried over anhydrousmagnesium sulfate, and the solvent was removed by distillation underreduced pressure. The residue was purified by chromatography throughsilica gel (eluted with a 9:1 by volume mixture of ethyl acetate andmethanol) to afford 5.5 g of the title compound as colorless crystals.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.43 (9H, singlet);

2.10-2.68 (2H, multiplet);

3.12 (3H, singlet);

3.10-3.40 (1H, broad singlet);

3.73 (2H, doublet, J=4.0 Hz);

4.32 (1H, triplet, J=7.0 Hz);

5.26 (1H, triplet, J=4.0 Hz);

6.68 (1H, broad singlet);

7.30 (1H, broad singlet).

1-(4S,4R)-1-(t-Butoxycarbonyl)-2-carbamoyl-4-(4-methoxybenzylthio)pyrrolidine

330 mg of sodium hydride (as a 55% w/w dispersion in mineral oil) wereadded, whilst ice-cooling, to a solution of 1.18 g of p-methoxybenzylmercaptan in 25 ml of dry dimethylformamide, and the mixture was stirredat room temperature for 30 minutes. At the end of this time, 2.14 g of(2S,4R)-1-(t-butoxycarbonyl)-2-carbamoyl-4-methanesulfonyloxypyrrolidine[prepared as described in step (3) above] were added to the mixture,which was then stirred at room temperature for 3 hours. The reactionmixture was then poured into an aqueous solution of sodium chloride andextracted with ethyl acetate. The extract was washed with an aqueoussolution of sodium chloride and dried over anhydrous magnesium sulfate,and the solvent was removed by distillation under reduced pressure. Theresidue was purified by chromatography through silica gel (eluted with a2:3 by volume mixture of cyclohexane and ethyl acetate) to afford 1.94 gof the title compound as an oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δppm;

1.43 (9H, singlet);

1.80-3.42 (5H, multiplet);

3.70 (2H, singlet);

3.78 (3H, singlet);

4.18 (1H, triplet, J=7.0 Hz);

5.96 (1H, broad singlet);

6.35 (1H, broad singlet); 6.79, 7.21 (4H, A₂ B₂, J=9.0Hz).

1-(5) (2S, 4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-pyrrolidine

1.92 g of (2S,4S)-1-(t-butoxycarbonyl)-2-carbamoyl-4-(4-methoxybenzylthio)pyrrolidine[prepared as described in step (4) above] was dissolved in 25 ml ofethyl acetate, and 26.2 ml of a 4N dioxane solution of hydrogen chloridewere added to the solution, whilst ice-cooling. The mixture was thenstirred at 0° to 5° C. for 2 hours and at room temperature for 30minutes. At the end of this time, it was poured into a saturated aqueoussolution of sodium bicarbonate, to make it weakly basic, and wasextracted with ethyl acetate. The extract was washed with an aqueoussolution of sodium chloride and dried over anhydrous magnesium sulfate.The solvent was then removed by distillation under reduced pressure, togive 1.36 g of the title compound as a powder, melting at 120°-121° C.

Nuclear Magnetic Resonance Spectrum (hexadeuterated dimethyl sulfoxide,60 MHz) δ ppm:

1.58-3.40 (7H, multiplet);

1.67 (2H, singlet);

1.78 (3H, singlet);

6.43 (1H, broad singlet);

6.78, 7.22 (4H, A₂ B₂, J=9.0 Hz); 7.31 (1H, broad singlet).

1-(5a) (2S, 4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-pyrrolidinehydrochloride

620 ml of a 4N solution of hydrogen chloride in ethyl acetate wereadded, whilst ice-cooling, to a solution of 91 g of (2S,4S)-1-t-butoxycarbonyl-2-carbamoyl-4-(4-methoxybenzylthio)pyrrolidine[prepared as described in step (4) above] in 2 l of ethyl acetate, andthen the mixture was stirred at room temperature for 4.5 hours. Thecrystals which precipitated were collected by filtration, washed withdiethyl ether and dried in vacuo, to give 63 g of the title compoundmelting at 192°-195° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ ; 1706, 1584, 1512.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm:

1.75-1.90 (1H, multiplet);

2.54-2.62 (1H, multiplet);

3.04-3.11 (1H, multiplet);

3.28-3.41 (2H, multiplet);

3.64 (2H, singlet);

3.65 (3H, singlet);

4.22 (2H, triplet, J=8.06 Hz);

6.80, 7.15 (4H, A₂ B₂, J=8.79 Hz).

1-(6a) (2,S, 4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-1-methylpyrrolidine

A solution of 0.29 g of sodium bicarbonate in 3 ml of water and 0.34 mlof 35% formalin were added dropwise in that order, whilst ice-cooling,to a suspension of 1 g of the compound obtained as described in step1-(5a) in 20 ml of acetonitrile, and then the mixture was stirred at 10°C. for 20 minutes. 0.25 g of sodium cyanoborohydride was then added tothe mixture, whilst ice-cooling, and then the mixture was stirred atroom temperature for 20 minutes. 0.5 ml of acetic acid was added, whilstice-cooling, to the mixture, which was then stirred at room temperaturefor 20 minutes. At the end of this time, the mixture was diluted with100 ml of ethyl acetate and washed, in turn, with a 1:1 by volumemixture of a 1N aqueous solution of sodium hydroxide and a saturatedaqueous solution of sodium chloride and then with a saturated aqueoussolution of sodium chloride. The organic phase was then dried overanhydrous magnesium sulfate and the solvent was distilled off underreduced pressure. The residue was purified by column chromatographythrough silica gel (Wakogel C-100, Wako Junyaku), eluted with a 95:5 byvolume mixture of chloroform and methanol, to give 0.92 g of the titlecompound. The melting point, infrared absorption spectrum and thenuclear magnetic resonance spectrum of this compound coincided withthose of the compound obtained as described in Preparation 1-(6), below.

1-(6) (2S, 4S)-2-Carbamoyl-4-(3-methoxybenzylthio)-1-methylpyrrolidine

0.07 ml of methyl iodide was added, whilst ice-cooling, to a solution of0.6 g of (2S, 4S)-2-carbamoyl-4-(4-methoxybenzylthio)pyrrolidine[prepared as described in step (5) above] dissolved in 4.5 ml of drydimethylformamide. The mixture was then stirred at 0° to 5° C. for 5minutes and at room temperature for 20 minutes. At the end of this time,the reaction mixture was poured into a saturated aqueous solution ofsodium bicarbonate and then extracted with ethyl acetate. The extractwas washed with an aqueous solution of sodium chloride and dried overanhydrous magnesium sulfate. The solvent was removed by distillationunder reduced pressure, and then the residue was subjected to columnchromatography using a Lobar column (Merck, LiChroprep Si 60, size B),and 252 mg of the title compound, melting at 113°-114° C., were obtainedas crystals from the fractions eluted with a 9:1 by volume mixture ofethyl acetate and methanol.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ ; 1636, 1609, 1512.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.58-3.36 (6H, multiplet);

2.35 (3H, singlet);

3.68 (2H, singlet);

3.78 (3H, singlet);

5.95 (1H, broad singlet);

6.84, 7.23 (4H, A₂ B₂, J=9.0 Hz);

7.20 (1H, broad singlet).

1-(7)-(2S,4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-1,1-dimethylpyrrolidiniumfluorosulfonate

0.123 ml of methyl fluorosulfonate was added, whilst ice-cooling, to asolution of 320 mg of (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)-1-methylpyrrolidine [prepared asdescribed in step (6) or (6a) above] dissolved in 7 ml of dry methylenechloride. The mixture was then stirred at the same temperature for 20minutes and at room temperature for 2 hours. At the end of this time,the solvent was removed by distillation under reduced pressure, and theresidue was repeatedly washed by decantation with diethyl ether and thendried under reduced pressure to afford 525 mg of the title compound asan oil.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm:

2.01-3.68 (5H, multiplet);

3.02 (2H, singlet);

3.03 (3H, singlet);

3.65 (3H, singlet);

3.68 (2H, singlet);

4.07 (1H, doublet of doublets, J=8.43 & 7.70 Hz);

6.81, 7.16 (4H, A₂ B₂, J=8.79Hz).

PREPARATION 2 (2S,4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-1-(2-fluoroethyl)-1-methylpyrrolidiniumfluorosulfonate 2-(1) (2S,4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-1-(2-fluoroethyl)pyrrolidine

0.4 ml of 1-bromo-2-fluoroethane, 3.83 g of sodium iodide and 0.38 g ofsodium bicarbonate were added to a solution of 1.2 g of (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)pyrrolidine dissolved in 12 ml ofdry dimethylformamide, whilst ice-cooling, and the mixture was stirredat room temperature for 20 minutes and then at 40° C. for 20 hours. Atthe end of this time, the reaction mixture was poured into a saturatedaqueous solution of sodium bicarbonate and extracted with ethyl acetate.The extract was washed with a saturated aqueous solution of sodiumchloride and dried over anhydrous magnesium sulfate. The solvent wasthen removed by distillation under reduced pressure, and the residue wassubjected to column chromatography through silica gel (KatayamaChemicals Industries Co., silica gel 60K070). 838 mg of the titlecompound, melting of 122°-123° C., were obtained as a powder from thosefractions eluted with ethyl acetate.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ ; 1636, 1610, 1510

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.55-3.40 (8H, multiplet);

3.69 (2H, singlet);

3.79 (3H, singlet);

4.47 (2H, doublet of triplets, J=47.0 & 6.0 Hz);

4.78 (1H, broad singlet);

7.02 (4H, A₂ B₂, J=9.0 Hz);

6.95-7.50 (1H, broad singlet).

2-(2) (2S,4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-1-(2-fluoroethyl)-1-methylpyrrodiniumfluorosulfonate

0.17 ml of methyl fluorosulfonate was added, whilst ice-cooling, to asolution of 630 mg of (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)-1-(2-fluoroethyl)-pyrrolidine[prepared as described in step (1) above] dissolved in 12 ml of drymethylene chloride. The mixture was stirred at the same temperature for30 minutes and then at room temperature for 5 hours. At the end of thistime, the solvent was removed by distillation under reduced pressure,and the residue was washed repeatedly by decantation with diethyl etherand dried under reduced pressure to afford 850 mg of the title compoundas an oil.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm:

1.84-4.73 (10H, multiplet);

3.18 (3H, singlet);

3.65 (3H, singlet);

3.68 (2H, singlet);

6.79-7.19 (4H, multiplet).

PREPARATION 3 (2S,4S)-1,1-Dimethyl-2-methylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate 3-(1) (2S,4R)-1-(t-Butoxycarbonyl)-2-methylcarbamoyl-4-hydroxypyrrolidine

9.91 ml of triethylamine were added at -40° C. to a solution of 15.03 gof (2S, 4R)-1-(t-butoxycarbonyl)-4-hydroxy-2-pyrrolidinecarboxylic aciddissolved in 250 ml of dry tetrahydrofuran, and then a solution of 6.81ml of ethyl chloroformate in 30 ml of dry tetrahydrofuran was added at-30° to -40° C. to the resulting mixture, which was then stirred at thesame temperature for 1 hour, 16.82 ml of a 40% by volume aqueousmethylamine solution were then added at -30° C., and the temperature ofthe reaction mixture was allowed to rise to room temperature; thereaction was then allowed to continue for 1 hour. At the end of thistime, the reaction mixture was mixed with a small amount of an aqueoussolution of sodium chloride and extracted thrice with ethyl acetate. Thecombined extracts were washed with an aqueous solution of sodiumchloride and dried over anhydrous magnesium sulfate. The solvent wasthen removed by distillation under reduced pressure, giving 12.76 g ofthe title compound as a colorless oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.44 (9H, singlet);

1.89-2.45 (2h, multiplet);

2.81 (3H, doublet, J=5.0 Hz);

3.23-3.71 (3H, multiplet);

4.12-4.68 (2H, multiplet);

6.70 (1H, broad singlet).

3-(2) (2S,4R)-1-(t-Butoxycarbonyl)-4-methanesulfonyloxy-2-methylcarbamoylpyrrolidine

7.11 ml of triethylamine were added, whilst ice-cooling, to a solutionof 11.29 g of (2S,4R)-1-(t-butoxycarbonyl)-2-methylcarbamoyl-4-hydroxypyrrolidine[prepared as described in step (1) above] dissolved in 120 ml of drytetrahydrofuran, and then 3.93 ml of methanesulfonyl chloride were addedto the resulting mixture, and the mixture was stirred at 0° to 5° C. for30 minutes and then at 15° C. for 30 minutes. It was then poured into anaqueous solution of sodium chloride and extracted with ethyl acetate.The extract was washed with an aqueous solution of sodium chloride anddried over anhydrous magnesium sulfate. The solvent was then removed bydistillation under reduced pressure, giving 11.58 g of the titlecompound as colorless crystals.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.46 (9H, singlet);

2.00-2.85 (2H, multiplet);

2.81 (3H, doublet, J=5.0 Hz);

3.03 (3H, singlet);

3.41-5.42 (4H, multiplet);

6.75 (1H, broad singlet).

3-(3) (2S,4S)-1-(t-Butoxycarbonyl)-4-(4-methoxybenzyl-thio)-2-methylcarbamoylpyrrolidine

1.80 g of sodium hydride (as a 55% w/w dispersion in mineral oil) wasadded, whilst ice-cooling, to a solution of 5.70 ml of 4-methoxybenzylmercaptan dissolved in 100 ml of dry tetrahydrofuran, and the mixturewas then stirred at 0° to 5° C. for 30 minutes. At the end of this time,a solution of 11.00 g of (2S,4R)-1-(t-butoxycarbonyl)-4-methanesulfonyloxy-2-methylcarbamoylpyrrolidine[prepared as described in step (2) above] in 80 ml of drydimethylformamide was added to the mixture, and the mixture was stirredat 34° C. for 4.5 hours. The reaction mixture was then poured into anaqueous solution of sodium chloride and extracted with ethyl acetate.The extract was washed with an aqueous solution of sodium chloride anddried over anhydrous magnesium sulfate. The solvent was then removed bydistillation under reduced pressure. The residue was purified by columnchromatography through silica gel (eluted with a 5:1 by volume mixtureof ethyl acetate and hexane) to afford 4.35 g of the title compound asan oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm;

1.42 (9H, singlet);

1.80-4.40 (6H, multiplet);

2.81 (3H, doublet, J=5.0 Hz);

3.70 (2H, singlet);

3.79 (3H, singlet);

6.39 (1H, broad singlet);

6.87, 7.26 (4H, A₂ B₂, J=9.0Hz).

3-(4) (2S, 4S)-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidine

52.5 ml of a 4N dioxane solution of hydrogen chloride were added, whilstice-cooling, to a solution of 4.00 g of (2S,4S)-1-(t-butoxycarbonyl)-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidine[prepared as described in step (3) above] dissolved in 50 ml of ethylacetate. The mixture was stirred at 0° to 50° C. for 30 minutes and thenat room temperature for 2 hours. At the end of this time, the reactionmixture was poured into a saturated aqueous solution of sodiumbicarbonate to make it weakly basic, and it was then extracted withethyl acetate. The aqueous layer was saturated with ammonium chlorideand then extracted with tetrahydrofuran. The extract was washed with anaqueous solution of sodium chloride and dried over anhydrous magnesiumsulfate, and the solvent was removed by distillation under reducedpressure. The residue was purified by column chromatography throughsilica gel (eluted with a 5:1 mixture by volume of ethyl acetate andmethanol), to afford 2.34 g of the title compound as colorless crystals,melting at 53°-54° C.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.42-3.89 (6H, multiplet);

2.74 (3H, doublet, J=5.0 Hz);

3.66 (2H, singlet);

3.76 (3H, singlet);

6.79, 7.17 (4H, A₂ B₂, J=9.0 Hz;

7.03-7.75 (2H, multiplet).

3-(5) (2S,4S)-4-(4-Methoxybenzylthio)-1-methyl-2-methylcarbamoylpyrrolidine

244 μl of methyl iodide and 300 mg of sodium bicarbonate were added,whilst ice-cooling, to a solution of 1.00 g of (2S,4S)-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidine [prepared asdescribed in step (4) above] dissolved in 6 ml of dry dimethylformamide.The mixture was then stirred at 0° to 5° C. for 1 hour and allowed tostand overnight at room temperature. At the end of this time, thereaction mixture was poured into an aqueous solution of sodium chlorideand extracted with ethyl acetate. The extract was washed with an aqueoussolution of sodium chloride and dried over anhydrous magnesium sulfate.The solvent was then removed by distillation under reduced pressure, andthe residue was purified by column chromatography through silica gel(eluted with a 10:1 by volume mixture of ethyl acetate and methanol), toafford 222 mg of the title compound as colorless crystals, melting at82°-84° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ ; 1655, 1512, 1251;

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.45-3.91 (6H, multiplet);

2.31 (3H, singlet);

2.80 (3H, doublet, J=5.0 Hz);

3.66 (2H, singlet);

3.77 (3H, singlet);

6.81, 7.20 (4H, A₂ B₂, J=9.0Hz),

6.85-7.60 (1H, multiplet).

3-(6) (2S,4S)-1,1-Dimethyl-2-methylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfate

280 μl of methyl fluorosulfonate were added, whilst ice-cooling, to asolution of 210 mg of (2S,4S)-4-(4-methoxybenzylthio)-1-methyl-2-methylcarbamoylpyrrolidine[prepared as described in step (5) above] dissolved in 30 ml of drymethylene chloride. The mixture was stirred at the same temperature for30 minutes and then at room temperature for 5 hours. At the end of thistime, the solvent was removed by distillation under reduced pressure,and the residue was washed repeatedly by decantation with diethyl etherand dried under reduced rpessure, to afford 281 mg of the title compoundas a colorless powder.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ ; 1681, 1512, 1248

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm:

1.95-2.43 (2H, multiplet):

2.62 (3H, singlet);

2.61-3.88 (3H, multiplet);

3.03 (3H, singlet);

3.10 (3H, singlet);

3.65 (3H, singlet);

3.68 (2H, singlet);

4.12 (1H, triplet, J=8.06 Hz);

6.83, 7.12 (4H, A₂ B₂, J=8.61Hz).

PREPARATION 4 (2S,4S)-1,1-Dimethyl-2-(N,N-dimethylcarbamoyl)-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate 4-(1) (2S,4R)-1-(t-Butoxycarbonyl)-2-(N,N-dimethylcarbamoyl)-4-hydroxypyrrolidine

3.84 ml of triethylamine was added, at -15° to -20° C., to a solution of5.8 g of (2S, 4R)-1-(t-butoxycarbonyl)-4-hydroxy-2-pyrrolidinecarboxylicacid dissolved in 85 ml of dry tetrahydrofuran, and then a solution of2.63 ml of ethyl chloroformate in 25 ml of dry tetrahydrofuran was addedto the resulting mixture at the same temperature. The reaction mixturewas then stirred for 2 hours, after which 19.75 ml of 50% by volumeaqueous dimethylamine was added to it at -20° to -25° C. The mixture wasthen stirred for 3 hours under ice cooling, after which is was allowedto stand overnight at room temperature. At the end of this time, themixture was poured into a mixture of 30 ml of concentrated hydrochloricacid and ice and extracted with ethyl acetate. The extract was washedwith an aqueous solution of sodium chloride and dried. The solvent wasthen removed by distillation under reduced pressure, and the residue waspurified by column chromatography through silica gel (eluted with a 9:1by volume mixture of ethyl acetate and methanol) to afford 429 mg of thetitle compound.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.42 (9H, singlet);

1.86-2.34 (2H, multiplet);

2.58-2.95 (1H, multiplet);

2.97 (3H, singlet);

3.10 (3H, singlet);

3.43-3.74 (2H, multiplet);

4.36-5.00 (2H, multiplet);

4-(2S,4R)-1-(t-Butoxycarbonyl)-2-(N,N-dimethylcarbamoyl)-4-methanesulfonyloxypyrrolidine

297 μl of methanesulfonyl chloride, followed by 537 μl of triethylamine,were added, whilst ice-cooling, to a solution of 993 mg of (2S,4R)-1-(t-butoxycarbonyl)-2-(N,N-dimethylcarbamoyl)-4-hydroxypyrrolidine[prepared as described in step (1) above] dissolved in 20 ml of drytetrahydrofuran. The mixture was stirred at 0° to 5° C. for 1 hour andthen at room temperature for 1 hour. At the end of this time, it wastreated and purified according to the procedure described in Preparation1-(3), to afford 1.05 g of the title compound as a colorless oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.43 (9H, singlet);

2.15-2.60 (2H, multiplet);

2.97 (3H, singlet);

3.07 (3H, singlet);

3.10, 3.13 (together 3H, each singlet);

3.83 (2H, doublet, J=4.0 Hz);

4.63-5.03 (1H, multiplet);

5.15-5.46 (1H, multiplet).

4-(3) (2S,4S)-1-(t-Butoxycarbonyl)-2-(N,N-dimethylcarbamoyl)-4-(4-methoxybenzylthio)pyrrolidine

151 mg of sodium hydroxide (as a 55% w/w dispersion in mineral oil) wereadded, whilst ice-cooling, to a solution of 532 mg of 4-methoxybenzylmercaptan dissolved in 10 ml of dry dimethylformamide. The mixture wasthen stirred at room temperature for 30 minutes, after which 1.05 g of(2S,4R)-1-(t-butoxycarbonyl)-2-(N,N-dimethylcarbamoyl)-4-methanesulfonyloxypyrrolidine[prepared as described in step (2) above] was added. The reactionmixture was then stirred at room temperature for 30 minutes and then at40° C. for 6 hours. At the end of this time, it was treated and purifiedaccording to the procedure described in Preparation 1-(4), to afford 385mg of the title compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1690, 1660,1605, 1585, 1515.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.35 and 1.38 (9H, singlet);

1.55-3.37 (5H, multiplet);

2.93 (3H, singlet);

3.00 (3H, singlet);

3.68 (2H, singlet);

3.77 (3H, singlet);

4.30-4.75 (1H, multiplet);

6.85, 7.25 (4H, A₂ B₂, J=9.0Hz).

4-(4) (2S,4S)-2-(N,N-Dimethylcarbamoyl)-4-(4-methoxybenzylthio)pyrrolidine

1 ml of a 4N dioxane solution of hydrogen chloride was added, whilstice-cooling, to a solution of 385 mg of (2S,4S)-1-(t-butoxycarbonyl)-2-(N,N-dimethylcarbamoyl)-4-(4-methoxybenzylthio)pyrrolidine[prepared as described in step (3) above] dissolved in 1 ml of ethylacetate, and the mixture was stirred at room temperature for 1.5 hours.At the end of this time, the reaction mixture was poured into asaturated aqueous solution of sodium bicarbonate to make it weaklybasic, and it was extracted with ethyl acetate. The extract was washedwith an aqueous solution of sodium chloride and dried over anhydrousmagnesium sulfate. The solvent was then removed by distillation underreduced pressure, and the residue was purified by column chromatographythrough silica gel (eluted with a 1:2 by volume mixture of ethyl acetateand methanol), to afford 163 mg of the title compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 3300, 1640,1605, 1590, 1510.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.21-1.78 (2H, multiplet);

2.09-3.98 (5H, multiplet);

2.94 (6H, singlet);

3.64 (2H, singlet);

3.75 (3H, singlet);

6.81, 7.21 (4H, A₂ B₂, J=9.0Hz).

4-(5) (2S,4S)-2-(N,N-Dimethylcarbamoyl)-4-(4-methoxybenzylthio)-1-methylpyrrolidine

84 mg of sodium bicarbonate and 41 μl of methyl iodide were added,whilst ice-cooling, to a solution of 163 mg of (2S,4S)-2-(N,N-dimethylcarbamoyl)-4-(4-methoxybenzylthio)pyrrolidine[prepared as described in step (4) above] dissolved in 1.5 ml of drydimethylformamide, and the mixture was stirred at room temperature for 4hours. At the end of this time, the reaction mixture was poured into asaturated aqueous solution of sodium bicarbonate and extracted withethyl acetate. The extract was washed with an aqueous solution of sodiumchloride and dried over anhydrous magnesium sulfate. The solvent wasthen removed by distillation under reduced pressure, and the residue waspurified by chromatography using a Lobar column (Merck, LiChroprep Si60,size A). 45 mg of the title compound were obtained, as an oil, from thefractions eluted with a 3:1 by volume mixture of ethyl acetate andmethanol.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1640, 1607,1580, 1510.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.56-2.18 (2H, multiplet);

2.20-3.60 (4H, multiplet);

2.34 (3H, singlet);

2.96 (3H, singlet);

3.10 (3H, singlet);

3.70 (2H, singlet);

3.78 (3H, singlet);

6.82, 7.22 (4H, A₂ B₂, J=9.0Hz).

4-(6) Methyl 1-(t-butoxycarbonyloxy)-4-hydroxyprolinate

2.2 g of sodium hydride (as a 55% w/w dispersion in mineral oil) wereadded, at 0° to 5° C., to a solution of 1.15 g of1-(t-butoxycarbonyl)-4-hydroxyproline dissolved in 100 ml of drydimethylformamide. The mixture was then stirred at room temperature for1.5 hours, after which it was cooled to 0° to 5° C., and 3.42 ml ofmethyl iodide were added to it. The reaction mixture was then allowed tostand overnight at room temperature. At the end of this time, it waspoured into a saturated aqueous solution of sodium chloride andextracted with ethyl acetate. The extract was washed with an aqueoussolution of sodium chloride and dried, after which the solvent wasremoved by distillation under reduced pressure, and the residue waspurified by column chromatography through silica gel (eluted with a 1:1by volume mixture of benzene and ethyl acetate) to afford 6.1 g of thetitle compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 3430, 1750,1700, 1670.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.41 (9H, singlet);

1.78-2.84 (3H, multiplet);

3.58 (2H, doublet, J=4.0 Hz);

3.71 (3H, singlet);

4.18-4.62 (2H, multiplet).

4-(7) (2S,4R)-1-(t-Butoxycarbonyl)-4-methanesulfonyloxy-2-methoxycarbonylpyrrolidine

2.02 ml of methanesulfonyl chloride, followed by 3.65 ml oftriethylamine were added, whilst ice-cooling, to a solution of 6.1 g ofmethyl 1-(t-butoxycarbonyl)-4-hydroxyprolinate [prepared as described instep (6) above] dissolved in 120 ml of dry tetrahydrofuran. The mixturewas stirred first at 0° to 5° C. for 1 hour and then at room temperaturefor 1 hour, after which it was poured into an aqueous solution of sodiumchloride and extracted with ethyl acetate. The extract was washed withan aqueous solution of sodium chloride and dried over anhydrousmagnesium sulfate. The solvent was then removed by distillation underreduced pressure, to afford 8.13 g of the title compound as an oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.47 (9H, singlet);

1.74-2.85 (2H, multiplet);

3.08 (3H, singlet);

3.79 (3H, singlet);

3.81 (2H, doublet, J=4.0 Hz);

4.15-4.65 (1H, multiplet);

5.12-5.41 (1H, multiplet).

4-(8) (2S,4S)-1-(t-Butoxycarbonyl-4-(4-methoxybenzylthio)-2-methoxycarbonylpyrrolidine

1.11 g of sodium hydride (as a 55% w/w dispersion in mineral oil) wasadded, whilst ice-cooling, to a solution of 3.51 ml of 4-methoxybenzylmercaptan dissolved in 60 ml of dry dimethylformamide, and the mixturewas stirred at room temperature for 30 minutes. At the end of this time,a solution of 8.13 g of (2S,4R)-1-(t-butoxycarbonyl)-4-methanesulfonyloxy-2-methoxycarbonylpyrrolidine[prepared as described in step (7) above] in 20 ml of drydimethylformamide was added dropwise to the mixture, which was thenstirred at room temperature for 15 minutes and then at 40° C. for 4hours. The reaction mixture was then poured into an aqueous solution ofsodium chloride and extracted with ethyl acetate. The extract was washedwith water, dried and freed from the solvent by distillation underreduced pressure. The residue was purified by column chromatographythrough silica gel (eluted with a 15:1 by volume mixture of benzene andethyl acetate), to afford 6.89 g of the title compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1745, 1690,1605, 1580, 1510

Nuclear Magnetic Resonance Spectrum (CDCl₂, 60 MHz) δ ppm:

1.40 (9H, singlet);

1.71-3.48 (5H, multiplet);

3.71 (3H, singlet);

3.78 (2H, singlet);

4.01-4.45 (1H, multiplet);

6.85, 7.25 (4H, A₂ B₂, J=9.0Hz).

4-(9) (2S, 4S)-4-(4-methoxybenzylthio)-2-methoxycarbonylpyrrolidine

27.3 ml of a 4N ethyl acetate solution of hydrogen chloride were added,whilst ice-cooling, to a solution of 5.22 g of (2S,4S)-1-(t-butoxycarbonyl)-4-(4-methoxybenzylthio)-2-methoxycarbonylpyrrolidine[prepared as described in step (8) above] dissolved in 14 ml of ethylacetate, and the mixture was stirred at room temperature for 1 hour. Thereaction mixture was then poured into a saturated aqueous solution ofsodium bicarbonate and extracted with ethyl acetate. The extract waswashed with an aqueous solution of sodium chloride and dried overanhydrous magnesium sulfate. The solvent was then removed bydistillation under reduced pressure, to give 3.3 g of the title compoundas an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 3250, 1735,1610, 1580, 1510.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.56-3.32(6H, multiplet); 3.67 (2H, singlet); 3.72 (3H, singlet); 3.78 (3H,singlet); 3.70-3.99 (1H, multiplet).

4-(10) (2S,4S)-4-(4-Methoxybenzylthio)-2-methoxycarbonyl-1-methylpyrrolidine

1.18 g of sodium bicarbonate and 0.876 ml of methyl iodide were added,whilst ice-cooling, to a solution of 3.3 g of (2S,4S)-4-(4-methoxybenzylthio)-2-methoxycarbonylpyrrolidine [prepared asdescribed in step (9) above] dissolved in 30 ml of drydimethylformamide, and the mixture was stirred at room temperature for 5hours. At the end of this time, the reaction mixture was poured into asaturated aqueous solution of sodium bicarbonate and extracted withethyl acetate. The extract was washed with an aqueous solution of sodiumchloride and dried over anhydrous magnesium sulfate. The solvent wasremoved by distillation under reduced pressure. The residue was purifiedby column chromatography over silica gel (eluted with a 1:2 by volumemixture of ethyl acetate and benzene), to afford 968 mg of the titlecompound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1740, 1730,1605, 1580, 1510.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.64-3.34(6H, multiplet); 2.37 (3H, singlet); 3.70 (2H, singlet); 3.81 (3H,singlet); 3.88 (3H, singlet); 6.83, 7.23 (4H, A₂ B₂, J=9.0 Hz).

4-(11) (2S,4S)-20(N,N-Dimethylcarbamoyl)-4-(4-methoxybenzylthio)-1-methylpyrrolidine

1.92 ml of a 1N aqueous solution of sodium hydroxide was added to asolution of 378 mg of (2S,4S)-4-(4-methoxybenzylthio)-2-methoxycarbonyl-1-methylpyrrolidine[prepared as described in step (10) above] dissolved in 3.84 ml ofmethanol, and the mixture was stirred at room temperature for 3 hours,At the end of this time, the mixture was neutralized by the addition of1.92 ml of 1N aqueous hydrochloric acid. The solvent was then removed bydistillation under reduced pressure, and the residue was dried, to givecrude (2S, 4S)-2-carboxy-4-(4-methoxybenzylthio)-1-methylpyrrolidine.

The whole of this crude compound was suspended in 7.3 ml of acetonitrileand 318 mg of N,N'-carbonyldiimidazole were added to the suspension, andthe resulting mixture was then stirred at 40° C. for 1 hour. At the endof this time, the mixture was allowed to cool to room temperature, andthen a solution of 559 mg of dimethylamine in 3.7 ml of tetrahydrofuranwas added to the mixture. The mixture was then allowed to stand at roomtemperature overnight. The solvent and an excess of dimethylamine wereremoved by distillation under reduced pressure. The residue was mixedwith an aqueous solution of sodium chloride and extracted with ethylacetate. The extract was dried over anhydrous magnesium sulfate and thesolvent was distilled off under reduced pressure. The residue waspurified according to the procedure described in Reference Example4-(5), to give 382 mg of the title compound as an oil.

4-(12) (2S,4S)-2-(N,N-Dimethylcarbamoyl)-4-(4-methoxybenzylthio)-1,1-dimethylpyrrolidiniumfluorosulfonate

139 μl of methyl fluorosulfonate were added, whilst ice-cooling, to asolution of 190 mg of (2S,4S)-2-(N,N-dimethylcarbamoyl)-4-(4-methoxybenzylthio)-1-methylpyrrolidine[prepared as described in step (5) or (11) above] dissolved in 3.8 ml ofmethylene chloride, and the mixture was stirred at room temperature for2 hours. At the end of this time, the solvent was distilled off underreduced pressure. The residue was repeatedly washed by decantation withhexane and dried under reduced pressure, to give 356 mg of the titlecompound as an oil.

Nuclear Magnetic Resonance Spectrum (D₂ O, 60 MHz) δ ppm: 1.58-4.58(12H, multiplet); 3.07 (6H, singlet); 3.84 (3H, singlet); 3.90 (2H,singlet); 6.90, 7.25 (4H, A₂ B₂, J=9.0 Hz).

PREPARATION 5 (3S)-1,1-Dimethyl-3-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate 5-(1)(3R)-1-t-Butoxycarbonyl-3methanesulfonyloxypyrrolidine

16.91 ml of triethylamine and 9.36 ml of methanesulfonyl chloride wereadded, in that order, whilst ice-cooling, to a solution of 25 g of(3R)-1-t-butoxycarbonyl-3-hydroxypyrrolidine dissolved in 250 ml of drytetrahydrofuran, and the mixture was stirred at 0° to 5° C. for 30minutes and then at 15° C. for 30 minutes. At the end of this time, themixture was poured into an aqueous solution of sodium chloride andextracted with ethyl acetate. The extract was washed with an aqueoussolution of sodium chloride and dried over anhydrous magnesium sulfate.The solvent was then removed by distillation under reduced pressure, togive 3.10 g of the title compound as a colorless oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.48 (9H,singlet); 1.91-2.45 (2H, multiplet); 3.04 (3H, singlet); 3.26-3.82 (4H,multiplet); 6.1-6.44 (1H, multiplet)

5-(2) (3S)-1-t-Butoxycarbonyl-3-(4-methoxybenzylthio)-pyrrolidine

5.32 g of sodium hydride (as a 55% w/w dispersion in mineral oil) wereadded, whilst ice-cooling, to a solution of 16.86 ml of 4-methoxybenzylmercaptan dissolved in 200 ml of dry dimethylformamide, and the mixturewas then stirred at room temperature for 30 minutes. At the end of thistime, a solution of 31.00 g of(3R)-1-t-butoxycarbonyl-3-methanesulfonyloxypyrrolidine [prepared asdescribed in step (1) above] in 50 ml of dry dimethylformamide was addedto the reaction mixture. The mixture was then stirred for 30 minuteswhilst ice-cooling, after which it was allowed to stand overnight atroom temperature. It was then poured into an aqueous solution of sodiumchloride and extracted with ethyl acetate. The extract was washed withan aqueous solution of sodium chloride and dried over anhydrousmagnesium sulfate. The solvent was distilled off under reduced pressure.The residue was purified by column chromatography through silica gel(eluted with a 5:1 by volume mixture of hexane and ethyl acetate), toafford 28.00 g of the title compound a pale-brown oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.46 (9H,singlet); 1.50-2.35 (2H, multiplet); 2.81-3.88 (5H, multiplet); 3.70(2H, singlet); 3.79 (3H, singlet); 6.83, 7.37 (4H, A₂ B₂, J=9.0Hz).

5-(3) (3S)-3-(4-Methoxybenzylthio)pyrrolidine hydrochloride

106 ml of a 4N ethyl acetate solution of hydrogen chloride were added,whilst ice-cooling, to a solution of 27.50 g of(3R)-1-t-butoxycarbonyl-3-(4-methoxybenzylthio)pyrrolidine [prepared asdescribed in step (2) above] dissolved in 100 ml of ethyl acetate, andthe mixture was stirred at 0° to 5° C. for 30 minutes and then at 25° C.for 2 hours. At the end of this time, the mixture was diluted with 200ml of diisopropyl ether, and the crystals which precipitated werecollected by filtration, to give 20.84 g of the title compound ascolorless crystals, melting at 125°-126° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ :

Nuclear Magnetic Resonance Spectrum (D₂ O, 60 MHz) δ ppm: 1.52-2.53 (2H,multiplet); 2.91-3.70 (5H, multiplet); 3.63 (2H, singlet); 3.67 (3H,singlet); 6.80, 7.16 (4H, A₂ B₂, J=9.0Hz).

5-(4) (3S)-3-(4-Methoxybenzylthio)-1-methylpyrrolidine

750 mg of (3S)-(4-methoxybenzylthio)pyrrolidine [which had been preparedby neutralization of 900 mg of (3S)-3-(4-methoxybenzylthio)pyrrolidinehydrochloride, prepared as described in step (3) above, with sodiumbicarbonate] were dissolved in 15 ml of dry acetonitrile, and 1.44 ml ofa 35% by volume solution of formaldehyde in water was added to thesolution. The reaction mixture was then stirred for 15 minutes, afterwhich it was neutralized by the addition of acetic acid; it was thenagain stirred for a further 2.5 hours. At the end of this time, thereaction mixture was poured into 200 ml of ethyl acetate, and themixture was washed with a 2N aqueous solution of potassium hydroxide andan aqueous solution of sodium chloride. The organic layer was dried overpotassium carbonate and the solvent was distilled off under reducedpressure. The residue was purified by column chromatography throughsilica gel (eluted with a 3:1 by volume mixture of ethyl acetate andmethanol), to afford 349 mg of the title compound as a colorless oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.40-3.49(7H, multiplet); 2.33 (3H, singlet); 3.69 (2H, singlet); 3.78 (3H,singlet); 6.86, 7.25 (4H, A₂ B₂, J=9.0 Hz).

5-(5) (3S)-1,1-Dimethyl-3-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate

118 μl of methyl fluorosulfonate were added, whilst ice-cooling, to asolution of 340 mg of (3S)-3-(4-methoxybenzylthio)-1-methylpyrrolidine[prepared as described in step (4) above] dissolved in 20 ml of drymethylene chloride. The mixture was then stirred at the same temperaturefor 30 minutes and then at room temperature for 3.5 hours. At the end ofthis time, the solvent was removed by distillation under reducedpressure, and the residue was repeatedly washed by decantation withdiethyl ether and dried under reduced pressure to afford 500 mg of thetitle compound as a colorless powder.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz); δ ppm: 1.86-2.05(1H, multiplet); 2.34-2.56 (1H, multiplet); 2.90 (3H, singlet); 3.01(3H, singlet); 2.98-3.73 (5H, multiplet); 3.65 (3H, singlet); 3.67 (2H,singlet); 6.82, 7.17 (4H, A₂ B₂, J=8.62 Hz).

PREPARATION 6 1,1-Dimethyl-4-(4-methoxybenzylthio)piperidiniumfluorosulfonate 6-(1) 4-Methanesulfonyloxy-1-methylpiperidine

13.3 ml of triethylamine and subsequently 7.4 ml of methanesulfonylchloride were added, whilst ice-cooling, to a solution of 10 g of4-hydroxy-1-methylpiperidine dissolved in 100 ml of dry tetrahydrofuran.The mixture was then stirred at 0° to 5° C. for 2 hours and then at roomtemperature for 1.5 hours, after which it was poured into an aqueoussolution of sodium chloride and extracted with ethyl acetate. Theextract was washed with an aqueous solution of sodium chloride and driedover anhydrous magnesium sulfate. The solvent was then distilled offunder reduced pressure, to afford 12.74 g of the title compound as anoil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.74-2.90(8H, multiplet); 2.28 (3H, singlet); 3.00 (3H, singlet); 4.73 (1H,multiplet).

6-(2) 4-(4-methoxybenzylthio)-1-methylpiperidine

10.9 ml of 4-methoxybenzyl mercaptan were dissolved in 55 ml of drydimethylformamide, and 3.4 g of sodium hydride (as a 55% w/w suspensionin mineral oil) were added to the solution, whilst ice-cooling. Themixture was then stirred at room temperature for 30 minutes. At the endof this time, a solution of 12.6 g of4-methanesulfonyloxy-1-methylpiperidine in 63 ml of drydimethylformamide was added to the mixture, which was then allowed tostand overnight at room temperature. The reaction mixture was thenpoured into an aqueous solution of sodium chloride and extracted withethyl acetate. The extract as washed with an aqueous solution of sodiumchloride and dried over anhydrous magnesium sulfate. The solvent wasthen removed by distillation under reduced pressure, and the residue waspurified by column chromatography through silica gel (eluted with a 1:4by volume mixture of ethyl acetate and methanol) to afford 9.01 g of thetitle compound as an oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.40-3.05(9H, multiplet); 2.23 (3H, singlet); 3.69 (2H, singlet); 3.78 (3H,singlet); 6.82, 7.23 (4H, A₂ B₂, J=9.0 Hz).

6-(3) 1,1-dimethyl-4-(4-methyoxybenzylthio)piperidinium fluorosulfonate

2.9 ml of methyl fluorosulfonate were added, whilst ice-cooling, to asolution of 8.95 g of 4-(4-methoxybenzylthio)-1-methylpiperidinedissolved in 300 ml of dry methylene chloride, and the mixture wasstirred at the same temperature for 20 minutes and then at roomtemperature for 2.5 hours. At the end of this time, the solvent wasremoved by distillation under reduced pressure, and the residue wawashed repeatedly by decantation with diethyl ether and dried underreduced pressure, to afford 12.76 g of the title compound as a colorlesspowder.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δ ppm: 1.75-1.93(2H, multiplet); 2.02-2.15 (2H, multiplet); 2.70-2.84 (2H, multiplet);3.05 (3H, singlet); 3.06 (3H, singlet); 3.24-3.97 (4H, multiplet); 3.74(3H, singlet); 3.78 (2H, singlet); 6.88, 7.26 (4H, A₂ B₂, J=8.79 Hz).

PREPARATION 7 (2S,4S)-2-(N,N-Dimethylcarbamoyl)-1-ethyl-1-methyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate 7-(1) (2S,4S)-1Ethyl-4-(4-methoxybenzylthio)-2-methoxycarbonylpyrrolidiniumfluorosulfonate

1.2 g of (2S,4S)-1-ethyl-4-(4-methyoxybenzylthio)-2-methoxycarbonylpyrrolidine[prepared as described in Preparation 4-(9)] was dissolved in 12 ml ofdry dimethylformamide, and 358 mg of sodium bicarbonate and 0.41 ml ofethyl iodide were added to the resulting solution, whilst ice-cooling.The mixture was then stirred at room temperature for 6 hours and then at45° to 50° C. for 3 hours. It was then poured into a saturated aqueoussolution of sodium bicarbonate and then extracted with ethyl acetate.The extract was washed with an aqueous solution of sodium chloride anddried over anhydrous magnesium sulfate. The solvent was then removed bydistillation under reduced pressure, and the residue was purified bycolumn chromatography through silica gel (eluted with a 1:4 by volumemixture of ethyl acetate and benzene) to afford 904 mg of the titlecompound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1740, 1615,1590, 1515.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.03 (3H,triplet, J=7.0 Hz); 2.72-3.43 (8H, multiplet); 3.70 (5H, singlet); 3.78(3H, singlet); 6.84, 7.25 (4H, A₂ B₂, J=9.0 Hz).

7-(2) (2S,4S)-2-(N,N-Dimethylcarbamoyl)-1-ethyl-4-(4-methoxybenzylthio)pyrrolidine

883 mg of (2S,4S)-1ethyl-4-(4-methoxybenzylthio)-2-methoxycarbonylpyrrolidine weredissolved in 8.6 ml of methanol, and 4.3 ml of a 1N aqueous solution ofsodium hydroxide were added to the resulting solution. The mixture wasthen stirred at room temperature for 2 hours, after which it wasneutralized by adding 4.3 ml of 1N aqueous hydrochloric acid. Thereaction mixture was then evaporated to dryness under reduced pressure,to give a crude product.

The resulting crude product was suspended in a 18 ml of dryacetonitrile, and 694 mg of N,N'-carbodiimidazole were added to thesuspension. The mixture was then stirred at 40° C. for 1 hour, afterwhich a solution of 1.89 ml of dimethylamine in 10 ml of tetrahydrofuranwas added to the mixture. The reaction mixture was then allowed to standat room temperature overnight, after which it was concentrated byevaporation under reduced pressure. The residue was mixed with anaqueous solution of sodium chloride and extracted with ethyl acetate andthe extract was washed with an aqueous solution of sodium chloride andthen dried over anhydrous magnesium sulfate. The solvent was thenremoved by distillation under reduced pressure, and the residue wassubjected to column chromatography using a Lobar column (Merck,LiChroprep Si60, size B). 795 mg of the title compound were obtained asan oil from the fractions eluted with a 10:1 by volume mixture of ethylacetate and methanol.

Infrared absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1640, 1610,1585, 1515.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm:

1.01 (3H, triplet, J=7.0 Hz); 1.57-3.73 (8H, multiplet); 2.91 (3H,singlet); 3.16 (3H, singlet); 3.70 (2H, singlet); 3.78 (3H, singlet);6.83, 7.27 (4H, A₂ B₂ J=9.0 Hz).

7-(3) (2S,4S)-2-(N,N-Dimethylcarbamoyl)-1-ethyl-1-methyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate

128 μl of methyl fluorosulfonate were added to a solution of 438 mg of(2S,4S)-2-(N,N-dimethylcarbamoyl)-1-ethyl-4-(4-methoxybenzylthio)pyrrolidinedissolved in 10 ml of methylene chloride, and the mixture was stirred atroom temperature for 2 hours. At the end of this time, the solvent wasremoved by distillation under reduced pressure, and the residue waswashed repeatedly by decantation with diethyl ether and dried underreduced pressure to afford the title compound as an oil.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.12 (3H,triplet, J=7.15 Hz); 1.96-2.08 (1H, multiplet); 2.62-3.51 (6H,multiplet); 2.79 (3H, singlet); 2.93 (3H, singlet); 2.95 (3H, singlet);3.65 (3H, singlet); 3.68 (2H, singlet); 4.55-4.60 (1H, multiplet).

PREPARATION 8 (2,S,4S)-1,1-Dimethyl-4-(4-methoxybenzylthio)-2-(4-morpholinocarbonyl)pyrrolidiniumfluorosulfonate 8-(1) (2S,4S)-4-(4-Methoxybenzylthio)-2-methoxycarbonyl-1-methylpyrrolidine

3.43 ml of 35% formalin were added to a solution of 2.25 g of (2S,4S)-4-(4-methoxybenzylthio)-2-methoxycarbonylpyrrolidine dissolved in 42ml of acetonitrile. Subsequently, 804 mg of sodium cyanoborohydride weredivided into three portions and added to the mixture over a period of 5minutes. The mixture was then stirred at room temperature for 30minutes. At the end of this time, the mixture was cooled, 1.3 ml ofacetic acid was added, and the reaction mixture was stirred at roomtemperature for 40 minutes. 40 ml of a 1N aqueous solution of sodiumhydroxide and an aqueous solution of sodium chloride were then added tothe mixture, after which it was extracted with ethyl acetate. Theextract was washed with an aqueous solution of sodium chloride and driedover anhydrous magnesium sulfate. The solvent was then removed bydistillation under reduced pressure, and the residue was purified by asimilar procedure to that described in Preparation 4-(10), to afford1.31 g of the title compound as an oil. The infra-red spectrum, nuclearmagnetic resonance spectrum and thin layer chromatograph of thiscompound were identical to those of the compound prepared as describedin Preparation 4-(10).

8-(2) (2S,4S)-4-(4-Methoxybenzylthio)-1-methyl-2-(4-morpholinocarbonyl)pyrrolidine

5.32 ml of a 1N aqueous solution of sodium hydroxide were added to asolution of 1.31 g of (2S,4S)-4-(4-methoxybenzylthio)-2-methoxycarbonyl-1-methylpyrrolidinedissolved in 11 ml of methanol, and the mixture was stirred at roomtemperature for 2 hours. At the end of this time, it was neutralizedwith 5.32 ml of 1N aqueous hydrochloric acid, and the reaction mixturewas freed from the solvent by evaporation under reduced pressure, andthe residue was dried and concentrated by evaporation under reducedpressure, to afford 1.5 g of crude (2S,4S)-2-carboxy-4-(4-methoxybenzylthio)-1-methylpyrrolidine.

500 mg of this crude (2S,4S)-2-carboxy-4-(4-methoxybenzylthio)-1-methylpyrrolidine were suspendedin 10 ml of acetonitrile, and 278 mg of N,N'-carbonyldiimidazole wereadded to the suspension, and the mixture was stirred at 40° C. for 1hour. The mixture was then allowed to cool to room temperature, afterwhich 187 μl of morpholine were added, and the reaction mixture wasstirred at room temperature for 2 hours and then allowed to standovernight. The solvent and excess morpholine were then removed bydistillation under reduced pressure, and the residue was mixed with anaqueous solution of sodium chloride and extracted with ethyl acetate.The extract was dried over anhydrous magnesium sulfate and the solventwas distilled off under reduced pressure. The residue was subjected tocolumn chromatography using a Lobar column (Merck, LiChroprep Si60, SizeB) and 418 mg of the title compound were obtained as an oil from thefractions eluted with a 3:1:1 by volume mixture of cyclohexane, ethylacetate and methanol.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1639, 1610,1511.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.50-3.33(6H, multiplet); 2.31 (3H, singlet); 3.64 (8H, broad singlet); 3.70 (2H,singlet); 3.78 (3H, singlet; 6.82, 7.21 (4H, A₂ B₂, J=9.0 Hz).

8-(3) (2S,4S)-1,1-Dimethyl-4-(4-methoxybenzylthio)-2-(4-morpholinocarbonyl)pyrrolidiniumfluorosulfonate

106 μl of methyl fluorosulfonate were added to a solution of 392 mg of(2S,4S)-4-(4-methoxybenzylthio)-1-methyl-2-(4-morpholinocarbonyl)pyrrolidinedissolved in 8 ml of methylene chloride, and the mixture was stirred atroom temperature for 2 hours. At the end of this time, the solvent wasremoved by distillation under reduced pressure, and the residue waswashed repeatedly by decantation with diethyl ether and dried underreduced pressure to afford 446 mg of the title compound as an oil.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.80-2.03(1H, multiplet); 2.67-3.90 (12H, multiplet); 2.98 (3H, singlet); 3.07(3H, singlet); 3.65 (3H, singlet); 3.68 (2H, singlet); 4.61 (1H, doubletof doublets, J=8.06, 6.23 Hz), 6.82, 7.17 (4H, A₂ B₂, J=8.61 Hz).

PREPARATION 9 (2S,4S)-1,1-dimethyl-4-(4-methoxybenzylthio)-2-(1-pyrrolidinocarbonyl)pyrrolidiniumfluorosulfonate 9-(1) (2S,4S)-4-(4-Methoxybenzylthio)-1-methyl-2-(1-pyrrolidinocarbonyl)pyrrolidine

The procedure described in Preparation 8-(2) was repeated, but using 500mg of crude (2S,4S)-2-carboxy-4-(4-methoxybenzylthio)-1-methylpyrrolidine [prepared asdescribed in Preparation 8-(2)], 278 mg of N,N'-carbonyldiimidazole and178 μl or pyrrolidine instead of morpholine, to afford 440 mg of thetitle compound.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1640, 1611, 1511,1444.

Nuclear Magnetic Resonance spectrum (CDCl₃, 60 MHz) δ ppm: 1.58-2.78(6H, multiplet); 2.30 (3H, singlet); 2.90-3.80 (8H, multiplet); 3.70(2H, singlet); 3.78 (3H, singlet); 6.84, 7.24 (4H, A₂ B₂, J=9.0 Hz).

9-(2) (2S,4S)-1,1,-Dimethyl-4-(4-methoxybenzylthio)-2-(1-pyrrolidinocarbonyl)pyrrolidiniumfluorosulfonate

The procedure described in Preparation 8-(3) was repeated, but using 418mg of (2S,4S)-4-(4-methoxybenzylthio)-1-methyl-2-(1-pyrrolidinocarbonyl)pyrrolidine,118 μl of methyl fluorosulfonate, to afford 472 mg of the title compoundas an oil.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.68-1.85(4H, multiplet); 1.94-2.10 (1H, multiplet); 2.69-3.85 (7H, multiplet);2.99 (3H, singlet); 3.03 (3H, singlet); 3.65 (3H, singlet); 3.67 (2H,singlet); 4.41 (1H, doublet of doublets, J=8.06, 6.60 Hz); 6.81, 7.17(4H, A₂ B₂, J=8.62 Hz).

PREPARATION 10 (2S,4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-1-ethyl-1-methylpyrrolidiniumfluorosulfonate 10-(1) (2S,4S)-2-Carbamoyl-1-ethyl-4-(4-methoxybenzylthio)pyrrolidine

0.362 ml of ethyl iodide and 315 mg of sodium bicarbonate to a solutionof 1000 mg of (2S, 4S)-2-carbamoyl-4-(4-methoxybenzylthio)pyrrolidinedissolved in 10 ml of dry dimethylformamide were added, whilstice-cooling, and the mixture was stirred at room temperature for 5.5hours. At the end of this time, the reaction mixture was poured into asaturated aqueous solution of sodium bicarbonate and extracted withethyl acetate. The extract was washed with an aqueous solution of sodiumchloride and dried over anhydrous magnesium sulfate, and then thesolvent was removed by distillation under reduced pressure. The residuewas subjected to column chromatography through silica gel (KatayamaChemicals Co., Silica Gel 60K070) and 560 mg of the title compound wereobtained as crystals, melting at 124°-125° C., from the fractions elutedwith ethyl acetate.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1632, 1509.

Nuclear Magnetic Resonance Spectrum (CDCl₃ +D₂ O, 270 MHz) δ ppm: 1.08(3H, triplet, J=7.33 Hz); 1.86-1.96 (1H, multiplet); 2.38-2.76 (4H,multiplet); 2.99-3.18 (3H, multiplet); 3.70 (2H, singlet); 3.80 (3H,singlet); 6.84, 7.21 (4H, A₂ B₂, J=8.79 Hz).

10-(2) (2S,4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-1-ethyl-1-methylpyrrolidiniumfluorosulfonate

0.43 ml of methyl fluorosulfonate was added, whilst ice-cooling, to asolution of 1.44 g of (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)-1-ethylpyrrolidine dissolved in30 ml of dry methylene chloride and the mixture was stirred at roomtemperature for 2 hours. At the end of this time, the solvent wasremoved by distillation under reduced pressure, and the residue waswashed repeatedly by decantation with diethyl ether and dried underreduced pressure to afford 2.0 g of the title compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1698, 1610,1512.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.12 (3H,triplet, J=7.33 Hz); 2.06-2.18 (1H, multiplet); 2.68-3.83 (6H,multiplet); 2.92 (3H, singlet); 3.64 (3H, singlet); 3.65 (2H, singlet);4.02-4.09 (1H, multiplet); 6.82, 7.16 (4H, A₂ B₂, J=8.42 Hz).

PREPARATION 11 (2S,4S)-2-Ethylcarbamoyl-1-ethyl-1-methyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate (1) (2S,4S)-1-t-Butoxycarbonyl-2-ethylcarbamoyl-4-hydroxypyrrolidine

15.25 ml of triethylamine and subsequently a solution of 10.48 ml ofethyl chloroformate in 50 ml of dry tetrahydrofuran were added at -25°C. to a solution of 23.13 g of (2S,4S)-1-t-butoxycarbonyl-4-hydroxy-2-pyrrolidinecarboxylic acid dissolvedin 350 ml of dry tetrahydrofuran, and the mixture was stirred at thesame temperature for 30 minutes. At the end of this time, a 70% byvolume aqueous ethylamine solution was added at -22° C., the reactiontemperature was allowed to rise gradually and the reaction finished whenthe temperature reached 10° C. The reaction mixture was then mixed witha small amount of an aqueous solution of sodium chloride, after which itwas extracted thrice with ethyl acetate. The combined extracts werewashed with an aqueous solution of sodium chloride and dried overanhydrous magnesium sulfate. The solvent was then removed bydistillation under reduced pressure, to afford 23.60 g of the titlecompound as a colorless oil.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.10 (3H,triplet, J=7.5 Hz); 1.44 (9H, singlet); 1.80-4.65 (10H, multiplet); 6.64(1H, broad singlet).

11-(2) (2S,4S)-1-t-Butoxycarbonyl-2-ethylcarbamoyl-4-methanesulfonyloxypyrrolidine

13.81 ml of triethylamine and subsequently 7.65 ml of methanesulfonylchloride were added, whilst ice-cooling, to a solution of 23.20 g of(2S, 4S)-1-t-butoxycarbonyl-2-ethylcarbamoyl-4-hydroxypyrrolidinedissolved in 250 ml of dry tetrahydrofuran, and then the mixture wasstirred at 0° to 5° C. for 30 minutes. The reaction mixture was thenpoured into an aqueous solution of sodium chloride and extracted withethyl acetate. The extract was washed with an aqueous solution of sodiumchloride and dried over anhydrous magnesium sulfate. The solvent wasthen removed by distillation under reduced pressure, to afford 26.54 gof the title compound as colorless crystals, melting at 138°-140° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1675, 1548, 1348. M&CFOLIO: 58042/FP-8907

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.12 (3H,triplet, J=7.5 Hz); 1.48 (9H, singlet); 2.05-4.59 (7H, multiplet); 3.03(3H, singlet); 5.07-5.43 (1H, multiplet); 6.58 (1H, broad singlet).

11-(3) (2S,4S)-1-t-Butoxycarbonyl-2-ethylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidine

3.57 g of sodium hydride (as a 55% w/w suspension in mineral oil) wasadded, whilst ice-cooling, to a solution of 11.31 ml of 4-methoxybenzylmercaptan dissolved in 150 ml of dry dimethylformamide and the mixturewas stirred at 0° to 5° C. for 30 minutes. A solution of 26.00 g of (2S,4S)-1-t-butoxycarbonyl-2-ethylcarbamoyl-4-methanesulfonyloxypyrrolidinein 100 ml of dry dimethylformamide was then added to the resultingmixture, and the whole was stirred at room temperature for 2 hours. Atthe end of this time, the reaction mixture was poured into an aqueoussolution of sodium chloride and extracted with ethyl acetate. Theextract was washed with an aqueous solution of sodium chloride and driedover anhydrous magnesium sulfate. At the end of this time, the solventwas removed by distillation under reduced pressure, and the residue waspurified by column chromatography through silica gel using a 1:1 byvolume mixture of hexane and ethyl acetate as an eluent, to afford 17.00g of the title compound as colorless crystals, melting at 92°-94° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1700, 1655, 1406.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.10 (3H,triplet, J=7.5 Hz); 1.43 (9H, singlet); 1.85-3.96 (7H, multiplet); 3.69(2H, singlet); 3.78 (3H, singlet); 4.18 (1H, triplet, J=7.5 Hz); 6.35(1H, broad singlet); 6.86, 7.24 (4H, A₂ B₂, J=9.0 Hz).

11-(4) (2S, 4S)-2-Ethylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidine

41.19 ml of a 4N ethyl acetate solution of hydrogen chloride were addedto a solution of 13.00 g of (2S,4S)-1-t-butoxycarbonyl-2-ethylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidinedissolved in 100 ml of ethyl acetate, and the mixture was stirred atroom temperature for 3 hours. At the end of this time, the reactionmixture was poured into a saturated aqueous solution of sodiumbicarbonate and extracted with ethyl acetate. The aqueous layer wassaturated with ammonium chloride and extracted with tetrahydrofuran. Thecombined extracts were washed with an aqueous solution of sodiumchloride and dried over anhydrous magnesium sulfate, and then thesolvent was removed by distillation under reduced pressure. The residuewas subjected to column chromatography through silica gel (eluted with a87:13 by volume mixture of ethyl acetate and methanol) to afford 8.00 gof the title compound as pale brown crystals, melting at 67°-68° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1649, 1512, 1240.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.10 (3H,triplet, J=7.5 Hz); 1.50-2.20 (1H, multiplet); 2.16 (1H, singlet);2.23-3.96 (7H, multiplet); 3.69 (2H, singlet); 3.78 (3H, singlet); 6.86,7.25 (4H, A₂ B₂, J=9.0 Hz); 7.53 (1H, broad singlet).

11-(5) (2S,4S)-2-Ethylcarbamoyl-1-ethyl-4-(4-methoxybenzylthio)pyrrolidine

301 μl of ethyl iodide and 314 mg of sodium bicarbonate were added,whilst ice-cooling, to a solution of 1.00 g of (2S,4S)-2-ethylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidine dissolved in 8ml of dry dimethylformamide, and the mixture was stirred at roomtemperature for 5 hours. At the end of this time, the reaction mixturewas poured into an aqueous solution of sodium chloride and extractedwith ethyl acetate. The extract was washed with an aqueous solution ofsodium chloride and dried over anhydrous magnesium sulfate, after whichthe solvent was removed by distillation under reduced pressure. Theresidue was subjected to column chromatography through silica gel(eluted with ethyl acetate) to afford 982 mg of the title compound ascolorless crystals, melting at 60°-61° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1651, 1512, 1252.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.06 (3H,triplet, J=7.5 Hz); 1.14 (3H, triplet, J=7.5 Hz); 1.56-3.90 (10H,multiplet); 3.69 (2H, singlet); 3.80 (3H, singlet); 6.82, 7.20 (4H, A₂B₂, J=9.0 Hz); 7.30 (1H, broad singlet).

11-(6) (2S,4S)-2-Ethylcarbamoyl-1-ethyl-1-methyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate

233 μl of methyl fluorosulfonate were added, whilst ice-cooling, to asolution of 910 mg of (2S,4S)-2-ethylcarbamoyl-1-ethyl-4-(4-methoxybenzylthio)pyrrolidinedissolved in 35 ml of dry methylene chloride, and the mixture wasstirred at room temperature for 3.5 hours. At the end of this time, thesolvent was removed by distillation under reduced pressure, and theresidue was washed by decantation with diethyl ether and dried underreduced pressure, to afford 1.20 g of the title compound as a pale brownoil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1680, 1513,1250.

Nuclear Magnetic resonance Spectrum (D₂ O, 270 MHz) δ ppm: 0.93 (3H,triplet, J=7.33 Hz); 1.12 (3H, triplet, J=7.33 Hz); 1.95-2.26 (1H,multiplet); 2.56-4.50 (9H, multiplet); 2.88 (3H, singlet); 3.65 (3H,singlet); 3.69 (2H, singlet); 6.83, 7.18 (4H, A₂ B₂, J=8.80 Hz).

PREPARATION 12 (2S,4S)-1-Ethyl-1-methyl-2-methylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate 12-(1) (2S,4S)-1-Ethyl-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidine

0.71 ml of ethyl iodide and 742 mg of sodium bicarbonate were added to asolution of 2.25 g of (2S,4S)-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidine dissolved in 20ml of dry dimethylformamide, and the mixture was stirred at 0° to 5° C.for 1 hour and then at room temperature for 5 hours. At the end of thistime, the reaction mixture was poured into an aqueous solution of sodiumchloride and extracted with ethyl acetate. The extract was washed withan aqueous solution of sodium chloride and dried over anhydrousmagnesium sulfate, after which the solvent was removed by distillationunder reduced pressure. The residue was purified by columnchromatography (eluted with ethyl acetate), to afford 1.87 g of thetitle compound as colorless crystals, melting at 68°-70° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1657, 1511, 1252.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.02 (3H,triplet, J=7.0 Hz); 1.58-3.91 (8H, multiplet); 2.80 (3H, doublet, J=5.0Hz); 3.67 (2H, singlet); 3.78 (3H, singlet); 6.85, 7.21 (4H, A₂ B₂,J=9.0 Hz); 7.10-7.60 (1H, broad singlet).

12-(2) (2S,4S)-1-Ethyl-1-methyl-2-methylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate

187 μl of methyl fluorosulfonate were added, whilst ice-cooling, to asolution of 700 mg of (2S,4S)-1-ethyl-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidinedissolved in 30 ml of dry methylene chloride, and the mixture wasstirred at room temperature for 4 hours. At the end of this time, thesolvent was removed by distillation under reduced pressure, and theresidue was washed repeatedly by decantation with diethyl ether anddried under reduced pressure to afford 950 mg of the title compound as acolorless oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1683, 1565,1280.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.12 (3H,triplet, J=7.33 Hz); 2.02-2.20 (1H, multiplet); 2.58-4.50 (7H,multiplet); 2.60 (3H, singlet); 2.87 (3H, singlet); 3.65 (3H, singlet);3.68 (2H, singlet); 6.82, 7.17 (4H, A₂ B₂, J=8.80 Hz).

PREPARATION 13 (2S,4S)-1,1-Dimethyl-2-ethylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate 13-(1) (2S,4S)-2-Ethylcarbamoyl-4-(4-methoxybenzylthio)-1-methylpyrrolidine

3.43 ml of 35% formalin and 804 mg of sodium cyanoborohydride were addedto a solution of 2.36 g of (2S,4S)-2-ethylcarbamoyl-4-(4-methoxybenzylthio)-pyrrolidine dissolved in 42ml of acetonitrile, and the mixture was stirred at room temperature for40 minutes. At the end of this time, a 1N aqueous solution of sodiumhydroxide was added, and the reaction mixture was poured into an aqueoussolution of sodium chloride and extracted with ethyl acetate. Theextract was washed with an aqueous solution of sodium chloride and driedover anhydrous magnesium sulfate, and the solvent was removed bydistillation under reduced pressure. The residue was purified by columnchromatography through silica gel (eluted with ethyl acetate) to afford1.93 g of the title compound as colorless crystals.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1655, 1513, 1252.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.12 (3H,triplet, J=7.5 Hz); 1.50-2.20 (1H, multiplet); 2.31 (3H, singlet);2.36-3.88 (7H, multiplet); 3.67 (2H, singlet); 3.78 (3H, singlet); 6.83,7.21 (4H, A₂ B₂, J=9.0 Hz); 7.20 (1H, broad singlet).

13-(2) (2S,4S)-1,1,-Dimethyl-2-ethylcarbamoyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate

264 μl of methyl fluorosulfonate were added, whilst ice-cooling, to asolution of 987 mg of (2S,4S)-2-ethylcarbamoyl-4-(4-methoxybenzylthio)-1-methylpyrrolidinedissolved in 40 ml of dry methylene chloride, and the mixture wasstirred at room temperature for 2 hours. At the end of this time, thesolvent was removed by distillation under reduced pressure, and theresidue was washed repeatedly by decantation with diethyl ether anddried under reduced pressure to afford 1.332 g of the title compound asa colorless oil.

Infrared Absorption Spectrum (CHCl₃) ν_(max) cm⁻¹ : 1680, 1510, 1240.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 0.94 (3H,triplet, J=7.33 Hz); 1.95-2.20 (1H, multiplet); 2.60-2.98 (1H,multiplet); 2.96 (3H, singlet); 3.00 (3H, singlet); 3.02-3.70 (5H,multiplet); 3.64 (3H, singlet); 3.67 (2H, singlet); 3.97 (1H, triplet,J=7.88 Hz); 6.81, 7.01 (4H, A₂ B₂, J=8.80 Hz).

PREPARATION 14(2S)-1,1-Dimethyl-4-(4-methoxybenzylthiomethyl)pyrrolidiniumfluorosulfonate 14-(1)(2S)-1-t-Butoxycarbonyl-2-(4-methoxybenzylthiomethyl)pyrrolidine

The procedure described in Preparation 5-(2) was repeated, but using12.16 g of (2S)-1-t-butoxycarbonyl-2-methanesulfonyloxymethylpyrrolidine[prepared by the methanesulfonylation of(2S)-1-t-butoxycarbonyl-2-hydroxymethylpyrrolidine], 7.3 ml of4-methoxybenzyl mercaptan and 2.3 g of sodium hydride (as a 55% w/wsuspension in mineral oil) in 100 ml of dry dimethylformamide, to afford13.93 g of the title compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1690, 1615,1590, 1518.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.20-4.15(9H, multiplet); 1.45 (9H, singlet); 3.70 (2H, singlet); 3.78 (3H,singlet); 6.82, 7.25 (4H, A₂ B₂, J=9.0 Hz).

14-(2) (2S)-2-(4-Methoxybenzylthiomethyl)pyrrolidine

The procedure described in Preparation 5-(3) was repeated, but using 5 gof (2S)-1-t-butoxycarbonyl-2-(4-methoxybenzylthiomethyl)pyrrolidine, toafford 2.51 g of the title compound as colorless crystals, melting at124°-126.5° C.

Infrared Absorption Spectrum (Nujol - trade mark) ν_(max) cm⁻¹ : 1615,1585, 1520.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.45-2.20(4H, multiplet); 2.25-3.96 (6H, multiplet); 3.76 (5H, singlet); 6.85 &7.32 (4H, A₂ B₂, J=9.0 Hz).

14-(3) (2S)-2-(4-Methoxybenzylthiomethyl)-1-methylpyrrolidine

The procedure described in Preparation 5-(4) was repeated, but using 2 gof (2S)-2-(4-methoxybenzylthiomethyl)pyrrolidine, 35% formalin and 848mg of sodium cyanoborohydride in the presence of 44 ml of acetonitrile,to afford 883 mg of the title compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1610, 1585,1510.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.40-3.22(9H, multiplet); 2.26 (3H, singlet); 3.68 (2H, singlet); 3.78 (3H,singlet); 6.83, 7.25 (4H, A₂ B₂, J=9.0 Hz).

14-(4) (2S)-1,1-Dimethyl-2-(4-methoxybenzylthiomethyl)-pyrrolidiniumfluorosulfonate

The procedure described in Preparation 5-(5) was repeated, but using 740mg of (2S)-2-(4-methoxybenzylthiomethyl)-1-methylpyrrolidine and 243 μlof methyl fluorosulfonate in the presence of 22 ml of methylenechloride, to afford 1.0 g of the title compound as crystals, melting at150°-153° C.

Infrared Absorption Spectrum (Nujol) ν_(max) cm⁻¹ : 1610, 1585, 1518.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.60-2.02(3H, multiplet); 2.26-3.51 (6H, multiplet); 2.64 (3H, singlet); 2.85(3H, singlet); 3.64 (5H, singlet); 6.82, 7.19 (4H, A₂ B₂, J=8.79 Hz).

PREPARATION 15(2R)-1,1-Dimethyl-4-(4-methoxybenzylthiomethyl)pyrrolidiniumfluorosulfonate

(1) The procedure described in Preparation 14-(1), (2), (3) and (4) wasrepeated, but using (2R)-1-t-butoxycarbonyl-2-hydroxymethylpyrrolidineas the starting material, to afford the title compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1610, 1585,1512.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.64-2.00(3H, multiplet); 2.25-3.48 (6H, multiplet); 2.64 (3H, singlet); 2.85(3H, singlet); 3.64 (5H, singlet); 6.82, 7.18 (4H, A₂ B₂, J=8.79 Hz).

PREPARATION 16 (2S,4S)-2-Carbamoyl-1-(2-hydroxyethyl)-4-(4-methoxybenzylthio)-1-methylpyrrolidiniumfluorosulfonate 16-(1) (2S,4S)-2-Carbamoyl-1-(2-hydroxyethyl)-4-(4-methoxybenzylthio)pyrrolidine

0.175 ml of 2-iodoethanol and 0.16 g of sodium bicarbonate were added,whilst ice-cooling, to a solution of 0.5 g of (2S,4S)-2-carbamoyl-4-(4-methoxybenzylthio)pyrrolidine [prepared asdescribed in Preparation 1-(5)] dissolved in 5 ml of drydimethylformamide, and the mixture was stirred at the same temperaturefor 1 hour, at room temperature for 2.5 hours, and at 40° C. for 19hours. The reaction mixture was then poured into a saturated aqueoussolution of sodium bicarbonate and extracted with ethyl acetate. Theextract was washed with an aqueous solution of sodium chloride and driedover anhydrous magnesium sulfate. The solvent was then removed bydistillation under reduced pressure, and the residue was subject tocolumn chromatography through silica gel (Wako Pure Chemicals, Ltd.;wako gel C-100). 0.465 g of the title compound was obtained as crystalsfrom the fractions eluted with a 95:5 by volume mixture of ethyl acetateand methanol.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1625, 1510, 1243.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δ ppm: 1.69 (1H,broad singlet); 1.92-1.99 (1H, multiplet); 2.55-2.72 (3H, multiplet);2.82-2.92 (1H, multiplet); 3.12-3.18 (3H, multiplet); 3.67 (2H, triplet,J=4.03 Hz); 3.71 (2H, singlet); 3.80 (3H, singlet); 5.42 (1H, broadsinglet); 6.85, 7.21 (4H, A₂ B₂, J=8.8 Hz); 7.35 (1H, broad singlet).

16-(2) (2S,4S)-2-Carbamoyl-1-(2-hydroxyethyl)-4-(4-methoxybenzylthio)-1-methylpyrrolidiniumfluorosulfonate

0.108 ml of methyl fluorosulfonate was added dropwise at roomtemperature to a solution of 0.38 of (2S,4S)-2-carbamoyl-1-(2-hydroxyethyl)-4-(4-methoxybenzylthio)pyrrolidinedissolved in 7.5 ml of dry methylene chloride, and the mixture wasstirred at the same temperature for 2 hours. At the end of this time,the solvent was removed by distillation under reduced pressure, and theresidue was washed by decantation with diethyl ether and dried underreduced pressure, to afford 0.396 g of the title compound as an oil.

PREPARATION 17 3-(4-Methoxybenzylthio)-1-methylquinuclidiniumfluorosulfonate 17-(1) 3-(4-Methoxybenzylthio)quinuclidine

The procedure described in Preparation 6-(2) was repeated, but using 3.7g of 3-methanesulfonyloxyquinuclidine (prepared by themethanesulfonylation of 3-quinuclidinol), 3.0 ml of 4-methoxybenzylmercaptan and 0.942 g of sodium hydride (as a 55% w/w suspension inmineral oil), to afford 1.74 g of the title compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1620, 1590,1510, 1247.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.02-2.31(5H, multiplet); 2.33-3.41 (7J, multiplet); 3.67 (2H, singlet); 3.82(3H, singlet); 6.86, 7.26 (4H, A₂ B₂, J=9.0 Hz).

17-(2) 3-(4-Methoxybenzylthio)-1-methylquinuclidinium fluorosulfonate

The procedure described in Preparation 6-(3) was repeated, but using 756mg of 3-(4-methoxybenzylthio)-quinuclidine and 271 μl of methylfluorosulfonate in the presence of 5 ml of methylene chloride, to afford1.078 g of the title compound as an oil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1609, 1590,1512, 1490, 1467.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δ ppm: 1.63-2.16(5H, multiplet); 2.70 (3H, singlet); 2.76-3.77 (7H, multiplet); 3.63(5H, singlet); 6.80, 7.15 (4H, A₂ B₂, J=8.61 Hz).

PREPARATION 18 (6S,8S)-1,4-Dimethyl-8-(4-methoxybenzylthio)-5-oxo-4-aza-1-azoniabicyclo[4.3.0]nonanefluorosulfonate 18-(1) (2S,4S)-1-(2-hydroxyethyl)-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidin

934 μl of 2-iodoethanol and 1.01 g of sodium bicarbonate were added,whilst ice-cooling, to a solution of 2.80 g of (2S,4S)-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidine dissolved in 18ml of dry dimethylformamide, and the mixture was stirred at 40° C. for24 hours. At the end of this time, the reaction mixture was poured intoan aqueous solution of sodium chloride and extracted with ethyl acetate.The extract was washed with an aqueous solution of sodium chloride anddried over anhydrous magnesium sulfate. The solvent was then removed bydistillation under reduced pressure, and the residue was purified bycolumn chromatography through silica gel (eluted with a 15:1 by volumemixture of ethyl acetate and methanol), to afford 2.22 g of the titlecompound as colorless crystals, melting at 88°-89.5° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1637, 1510, 1240.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δ ppm: 1.66-2.05(2H, multiplet); 2.50-2.91 (4H, multiplet); 2.82 (3H, doublet, J=4.77Hz); 3.07-3.21 (3H, multiplet); 3.56-3.75 (2H, multiplet); 3.69 (2H,singlet); 3.80 (3H, singlet); 6.84, 7.20 (4H, A₂ B₂, J=8.79 Hz); 7.42(1H, broad singlet).

18-(2) (2S,4S)-1-(2-Methanesulfonyloxyethyl)-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidine

1.06 ml of triethylamine and subsequently 584 μl of methanesulfonylchloride were added, whilst ice-cooling, to a solution of 2.13 g of (2S,4S)-1-(2-hydroxyethyl)-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidinedissolved in 45 ml of dry tetrahydrofuran, and the mixture was stirredat 0° to 5° C. for 30 minutes. At the end of this time, the crystalswhich precipitated were collected by filtration and washed withtetrahydrofuran. The filtrate and washings were combined and dried overanhydrous magnesium sulfate, and the solvent was removed by distillationunder reduced pressure, to afford 2.50 g of the title compound as anoil.

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1664, 1510,1350.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 60 MHz) δ ppm: 1.55-4.10(8H, multiplet); 2.81 (3H, doublet, J=5.0 Hz); 3.05 (3H, singlet); 3.70(2H, singlet); 3.80 (3H, singlet); 4.18-4.49 (2H, multiplet); 6.87, 7.26(4H, A₂ B₂, J=9.0 Hz); 7.55 (1H, broad singlet).

18-(3) (6S,8S)-8-(4-Methoxybenzylthio)-4-methyl-5-oxo-1,4-diazabicyclo[4.3.0]nonane

347 mg of sodium hydride (as a 55% w/w suspension in mineral oil) wasadded, whilst ice-cooling, to a solution of 2.64 g of (2S,4S)-1-(2-methanesulfonyloxyethyl)-4-(4-methoxybenzylthio)-2-methylcarbamoylpyrrolidinedissolved in 30 ml of dry dimethylformamide, and the mixture was stirredat 0° to 5° C. for 30 minutes and then at 30° C. for 2 hours. Thereaction mixture was then poured into an aqueous solution of sodiumchloride and extracted with ethyl acetate. The extract was washed withan aqueous solution of sodium chloride, dried over anhydrous magnesiumsulfate and freed from the solvent by distillation under reducedpressure. The residue was purified by column chromatography throughsilica gel (eluted with a 5:1 by volume mixture of acetonitrile andmethanol), to afford 1.75 g of the title compound as an oil.

Infrared Absorption Spectrum (CHCl₃) ν_(max) cm⁻¹ : 1637, 1508, 1240.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δ ppm: 1.88-2.01(1H, multiplet); 2.59 (1H, doublet of triplets, J=13.18, 8.06 Hz);2.75-2.98 (3H, multiplet); 2.94 (3H, singlet); 3.00-3.24 (3H,multiplet); 3.30 (1H, triplet, J=8.06 Hz); 3.48-3.62 (1H, multiplet);3.70 (2H, singlet); 3.80 (3H, singlet); 6.84, 7.33 (4H, A₂ B₂, J=8.80Hz).

18-(4) (6S,8S)-1,4-Dimethyl-8-(4-methoxybenzylthio)-5-oxo-4-aza-1-azoniabicyclo[4.3.0]nonanefluorosulfonate

461 μl of methyl fluorosulfonate was added, whilst ice-cooling, to asolution of 1.71 g of (6S,8S)-8-(4-methoxybenzylthio)-4-methyl-5-oxo-1,4-diazabicyclo-[4.3.0]nonanedissolved in 60 ml of methylene chloride, and the mixture was stirred atroom temperature for 2 hours. At the end of this time, the mixture wasdiluted with diethyl ether, and the resulting crystals were collected byfiltration and dried under reduced pressure, to afford 2.09 g of thetitle compound as colorless crystals, melting at 208°-210° C.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1651, 1512, 1295.

Nuclear Magnetic Resonance Spectrum (hexadeuterated dimethyl sulfoxide,270 MHz) δ ppm: 2.16-2.33 (1H, multiplet); 2.79-2.95 (1H, multiplet);2.89 (3H, singlet); 3.23 (3H, singlet); 3.38 (1H, broad singlet);3.56-4.02 (6H, multiplet); 3.74 (3H, singlet); 3.80 (2H, singlet); 4.37(1H, triplet, J=8.30 Hz); 6.90, 7.26 (4H, A₂ B₂, J=8.79 Hz).

PREPARATION 19 3-Mercapto-2-pyrrolidinone trifluoromethanesulfonate

20 ml of trifluoroacetic acid and 0.41 ml of trifluoromethanesulfonicacid were added, whilst ice-cooling, to a solution of 949 mg of3-(4-methoxybenzylthio)pyrrolidin-2-one in 4 ml of anisole, and then themixture was stirred at room temperature for 30 minutes. At the end ofthis time, the reaction mixture was concentrated by evaporation underreduced pressure to leave a residue, which was purified by columnchromatography through silica gel, eluted with a 10:1 by volume mixtureof ethyl acetate and methanol, to give 728 mg of the title compound asan oil.

Nuclear Magnetic Resonance Spectrum (60 MHz, CDCl₃) δ ppm: 1.75-3.05(3H, multiplet); 3.30-4.04 (3H, multiplet); 8.12 (1H, broad singlet);9.32 (1H, broad singlet).

PREPARATION 20 4-Mercapto-2-pyrrolidinone

20-(1) 15.6 g of triphenylphosphine were added to a suspension of 3 g of4-hydroxy-2-pyrrolidinone in 200 ml of tetrahydrofuran, and then themixture was stirred at room temperature for 5 minutes, after which itwas cooled to -20° C. A solution of 9.3 ml of diethyl azodicarboxylatein 9 ml of tetrahydrofuran was added dropwise, whilst cooling at -12° C.to -20° C., to the previous solution. The mixture was then stirred at0°-5° C. for 5 minutes, after which it was again cooled to -20° C. 4.2ml of thioacetic acid were then added dropwise to the mixture, whilstcooling at -18° C. to -20° C. The mixture was then warmed to 0°-5° C.and stirred at that temperature for 2 hours. At the end of this time,the reaction mixture was concentrated by evaporation under reducedpressure. The residue was purified first by column chromatographythrough silica gel, eluted with a 10:1 by volume mixture of ethylacetate and methanol, and then by column chromatography through silicagel, eluted with a 2:1 by volume mixture of acetonitrile and benzene, togive 2.45 g of 4-acetylthio-2-pyrrolidinone as colorless crystals.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 90 MHz) δ ppm: 2.00-4.44(5H, multiplet); 2.31 (3H, singlet); 7.13 (1H, broad singlet).

20-(2) 1.82 of the product obtained in step (1) were dissolved in 30 mlof methanol. 2.3 ml of a 28% w/v methanolic solution of sodium methoxidewere added dropwise, whilst ice-cooling, to the previous solution, andthen the mixture was stirred for 30 minutes. 12 ml of 1N hydrochloricacid were then added, whilst ice-cooling, to the reaction mixture, whichwas then concentration by evaporation under reduced pressure to leave apowdery residue. The residue was extracted with 50 ml of ethyl acetateand the extract was dried over anhydrous sodium sulfate. The extract wasconcentrated by evaporation under reduced pressure to give 1.35 g of thetitle compound as colorless crystals.

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1687, 1681, 1250.

Nuclear Magnetic Resonance Spectrum (CDCl₃, 270 MHz) δppm: 1.95 (1H,doublet, J=7.0 Hz); 2.30 (1H, doublet of doublets, J=17.2 & 6.6 Hz);2.80 (1H, doublet of doublets, J=17.2 & 7.1 Hz); 3.31 (1H, doublet ofdoublets of doublets, J=9.9, 5.2 & 0.8 Hz); 3.59-3.73 (1H, multiplet);3.80 (1H, doublet of doublets of doublets, J=9.9, 7.3 & 0.7 Hz); 6.13(1H, broad singlet).

PREPARATIONS 21 TO 25

Following procedures similar to those described above in Preparations 1to 4, the following compounds were also prepared:

Preparation 21 (2S,4S)-1,1-Dimethyl-4-(4-methoxybenzylthio)-2-methoxycarbonylpyrrolidiniumfluorosulfonate

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1747, 1512.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 2.16-2.29 (1H,multiplet); 2.74-2.92 (1H, multiplet); 3.05 (3H, singlet); 3.12 (3H,singlet); 3.38-3.73 (3H, multiplet); 3.65 (3H, singlet); 3.66 (3H,singlet); 3.68 (2H, singlet); 4.32 (1H, doublet of doublets, J=10.99 &7.69 Hz); 7.16, 7.82 (4H, A₂ B₂, J=8.61 Hz).

Preparation 22 (2R,4S)-2-Carbamoyl-4-(4-methoxybenzylthio)-1,1-dimethylpyrrolidiniumfluorosulfonate

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1698, 1512.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 2.19-2.30 (1H,multiplet); 2.57-2.70 (1H, multiplet); 2.93 (3H, singlet); 3.15 (3H,singlet); 3.30 (1H, doublet of doublets, J=12.09 & 7.51 Hz); 3.47-3.60(1H, multiplet); 3.66 (3H, singlet); 3.69 (2H, singlet); 3.77 (1H,doublet of doublets, J=12.09 & 8.06 Hz); 4.26 (1H, triplet, J=8.43 Hz);6.82, 7.18 (4H, A₂ B₂, J=8.61 Hz).

Preparation 23 (2R,4S)-1,1-Dimethyl-2-(N,N-dimethylcarbamoyl)-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1652, 1511.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 2.17-2.29 (1H,multiplet); 2.46-2.58 (1H, multiplet); 2.78 (3H, singlet); 2.94 (3H,singlet); 2.98 (3H, singlet); 3.10 (3H, singlet); 3.26 (1H, doublet ofdoublets, J=12.09 & 6.96 Hz); 3.51-3.63 (1H, multiplet); 3.65 (3H,singlet); 3.69 (2H, singlet); 3.84 (1H, doublet of doublets, J=12.09 &8.62 Hz); 4.75 (1H, doublet of doublets, J=7.69 & 6.96 Hz); 6.82, 7.17(4H, A₂ B₂, J=8.78 Hz).

Preparation 24 (2S,4S)-2-Cyclopropylcarbamoyl-1,1-dimethyl-4-(4-methoxybenzylthio)pyrrolidiniumfluorosulfonate

Infrared Absorption Spectrum (liquid film) ν_(max) cm⁻¹ : 1685, 1532,1512.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 0.26-2.66 (4H,multiplet); 2.00-3.65 (6H, multiplet); 2.96 (3H, singlet); 2.98 (3H,singlet); 3.65 (3H, singlet); 3.68 (2H, singlet); 3.92 (1H, triplet,J=7.86 Hz); 6.81, 3.17 (4H, A₂ B₂, J=8.80 Hz).

Preparation 25 (6S,8S)-5-Oxo-8-(4-methoxybenzylthio)-1-methyl-4-aza-1-azoniabicyclo[4.3.0]nonane fluorosulfonate

Infrared Absorption Spectrum (KBr) ν_(max) cm⁻¹ : 1680, 1609, 1512,1246.

Nuclear Magnetic Resonance Spectrum (D₂ O, 270 MHz) δppm: 2.10-2.24 (1H,multiplet); 2.73-2.90 (1H, multiplet); 3.65 (3H, singlet); 3.67 (2H,singlet); 3.36-3.85 (7H, multiplet); 4.18 (1H, triplet, J=8.43 Hz);6.82, 7.17 (4H, A₂ B₂, J=8.79 Hz).

We claim:
 1. A compound of the formula (I): ##STR39## in which: R^(a)represents a group of formula (II): ##STR40## and in which: one of thesymbols R' represents a bond to the remainder of the compound of formula(I), one of the symbols R' is R² and in said formula (II) the others ofthe symbols R' all represent hydrogen atoms;R¹ represents a hydrogenatom or a methyl group R² represents a hydrogen atom, a C₁ -C₆ alkylgroup, a C₁ -C₆ alkyl group having at least one substituent selectedfrom the group consisting of substituents (a), a halogen atom, a hydroxygroup, a C₁ -C₆ alkoxy group, an amino group, a C₁ -C₆ alkanoylaminogroup, a C₁ -C₆ alkanoyloxy group, a C₁ -C₆ alkanoyl group, a carboxygroup, a C₂ -C₇ alkoxycarbonyl group, a cyano group, a group of formula--S(O)_(j) R⁹ where j is zero or an integer 1 or 2 and R⁹ represents aC₁ -C₆ alkyl group; or a group of formula --CONR⁶ R⁷ wherein R⁶ and R⁷are independently selected from the group consisting of hydrogen atoms,C₁ -C₆ alkyl groups, C₁ -C₆ cycloalkyl groups, C₂ -C₆ alkenyl groups, C₂-C₆ alkynyl groups and C₁ -C₆ alkyl groups having at least onesubstituent selected from the group consisting of substituents (a), orR⁶ and R⁷ together represent a C₁ -C₆ alkylene group or a C₁ -C₆alkylene group whose carbon chain is interupted by an oxygen or sulfuratom or by a group of formula ##STR41## wherein R⁸ represents a hydrogenatom, a C₁ -C₆ alkyl group or a C₁ -C₆ alkanoyl group, or R⁶ and R⁷together represent said alkylene group having at least one substituentselected from the group consisting of substituents (b), defined below:R³ and R⁴ are independently from the group consisting of C₁ -C₆ alkylgroups, C₂ -C₆ alkenyl groups, C₂ -C₆ alkynyl groups, aralkyl groupswhere the alkyl part is C₁ -C₃ alkyl and the aryl part is C₆ -C₁₀carbocyclic aromatic which is unsubstituted or has at least onesubstituent selected from the group consisting of substituents (c),cycloalkylalkyl groups where the alkyl part is C₁ -C₃ alkyl and thecycloalkyl part is C₃ -C₆, and C₁ -C₆ alkyl groups having at least onesubstituent selected from the group consisting of substituents (a), orone of R³ and R⁴, together with R², represents a C₁ -C₆ alkylene groupor a C₁ -C₆ alkylene group whose carbon chain is interupted by an oxygenor sulfur atom or by a group of formula ##STR42## wherein R⁸ is asdefined above, or one of R³ and R⁴, together with R², represents saidalkylene group having at least one substituent selected from the groupconsisting of substituents (b), defined below; and --COOR⁵ represents acarboxy group (--COOH) or a carboxylate group (--COO⁻), l, m and n areindependently zero, or an integer from 1 to 3, provided that (m+n) is aninteger from 2 to 6; Y represents a single bond, an oxygen atom, asulfur atom or a group of formula ##STR43## wherein R⁸ is as definedabove, substituents (a): hydroxy groups, cyano groups, carbamoyloxygroups, azido groups, carboxy groups, nitro groups, oxo groups, halogenatoms, C₁ -C₆ alkoxy groups, C₁ -C₆ alkanoyl groups, C₁ -C₆ alkanoyloxygroups, C₁ -C₆ alkanoylamino groups, C₂ -C₇ alkoxycarbonyl groups,groups of formula --NR¹⁰ R¹¹ and --CONR¹² R¹³ in which R¹⁰, R¹¹, R¹² andR¹³ are independently selected from the group consisting of hydrogenatoms, C₁ -C₆ alkyl groups and C₁ -C₆ alkanoyl groups, groups of formula--SO₂ NR¹⁴ R¹⁵ and --S(O)_(k) R¹⁶ wherein R¹⁴, R¹⁵ and R¹⁶ areindependently selected from the group consisting of C₁ -C₆ alkyl groupsand k is zero or an integer 1 or 2, and groups of formula --NHSO₂ R¹⁷,--N═CR¹⁸ NR¹⁹ R²⁰, --N═CR²¹ CR²² ═NR²³ and --C(═NH)NR²⁴ R²⁵ wherein R¹⁷to R²⁵ are independently selected from the group consisting of hydrogenatoms and C₁ -C₆ alkyl groups; substituents (b): hydroxy groups, cyanogroups, carbamoyl groups, oxo groups, halogen atoms, C₁ -C₆ alkyl groupsand C₁ -C₆ alkoxy groups; substituents (c):C₁ -C₄ alkyl groups, C₁ -C₄alkoxy groups, C₁ -C₄ haloalkyl groups, C₁ -C₃ alkylenedioxy groups,halogen atoms, cyano groups and nitro groups;or a pharmaceuticallyacceptable salt thereof.
 2. The compound of claim 2, in which R¹represents a methyl group.
 3. The compound of claim 1, in which:one ofthe symbols R' represents a bond to the remainder of the compound offormula (I), one more of the symbols R' is R² and the others of thesymbols R' all represent hydrogen atoms; R¹ represents a hydrogen atomor a methyl group; R² represents a hydrogen atom, a C₁ -C₄ alkyl group,a C₁ -C₄ alkyl group having at least one substituent selected from thegroup consisting of substituents (a'), defined below, a halogen atom, ahydroxy group, a C₁ -C₄ alkoxy group, an amino group, a C₁ -C₆alkanoylamino group, a C₁ -C₆ alkanoyloxy group, a C₁ -C₆ alkanoylgroup, a carboxy group, a C₂ -C₅ alkoxycarbonyl group, a cyano group, agroup of formula --S(O)_(j) R⁹ wherein j is zero or an integer 1 or 2and R⁹ represents a C₁ -C₄ alkyl group; or a group of formula --CONR⁶ R⁷wherein R⁶ and R⁷ are independently selected from the group consistingof hydrogen atoms, C₁ -C₄ alkyl groups, C₃ -C₆ cycloalkyl groups, C₂ -C₄alkenyl groups, C₃ -C₄ alkynyl groups and C₁ -C₄ alkyl groups having atleast one substituent selected from the group consisting of substituents(a'), or R⁶ and R⁷ together represent a C₂ -C₄ alkylene group or a C₂-C₄ alkylene group whose carbon chain is interupted by an oxygen orsulfur atom or by a group of formula ##STR44## wherein R⁸ represents ahydrogen atom, a C₁ -C₄ alkyl group of a C₁ -C₆ alkanoyl group, or R⁶and R⁷ together represent said alkylene group having at least onesubstituent selected from the group consisting of substituents (b),defined in claim 1; R³ and R⁴ are independently selected from the groupconsisting of C₁ -C₄ alkyl groups, C₃ -C₄ alkenyl groups, C₃ -C₄ alkynylgroups, benzyl groups, cycloalkylalkyl groups where the alkyl part is C₁-C₃ alkyl and the cycloalkyl part is C₃ -C₆, and C₁ -C₄ alkyl groupshaving at least one substituent selected from the group consisting ofsubstituents (a'), or one of R³ and R⁴, together with R², represents aC₂ -C₄ alkylene group or a C₂ -C₄ alkylene group whose carbon chain isinterupted by an oxygen or sulfur atom or by a group of formula##STR45## wherein R⁸ is as defined in claim 1, or one of R³ and R⁴,together with R², represents said alkylene group having at least onesubstituent selected from the group consisting of substituents (b),defined below; and --COOR⁵ represents a carboxy group (--COOH) or acarboxylate group (--COO⁻); l is zero or 1 and (m+n) is an integer from2 to 6; Y represents a single bond, an oxygen atom, a sulfur atom or agroup of formula ##STR46## wherein R⁸ is as defined in claim 1,substituents (a'): hydroxy groups, cyano groups, carbamoyloxy groups,carboxy groups, nitro groups, halogen atoms, C₁ -C₃ alkoxy groups, C₁-C₆ alkanoyl groups, C₁ -C₆ alkanoyloxy groups, C₁ -C₆ alkanoylaminogroups, C₂ -C₅ alkoxycarbonyl groups, groups of formula --NR¹⁰ R¹¹ and--CONR¹² R¹³ in which R¹⁰, R¹¹ R¹² and R¹³ are independently selectedfrom the group consisting of hydrogen atoms, C₁ -C₄ alkyl groups and C₁-C₆ alkanoyl groups, groups of formula --SO₂ NR¹⁴ R¹⁵ and --S(O)_(k) R¹⁶wherein R¹⁴, R¹⁵ and R¹⁶ are independently selected from the groupconsisting of C₁ -C₄ alkyl groups and k is zero or an integer 1 or 2,and groups of formula --NHSO₂ R¹⁷, --N═CR¹⁸ NR¹⁹ R²⁰, --N═CR²¹ CR²²═NR²³ and --C(═NH)NR²⁴ R²⁵ wherein R¹⁷ to R²⁵ are independently selectedfrom the group consisting of hydrogen atoms and C₁ -C₄ alkyl groups;or apharmaceutically acceptable salt thereof.
 4. The compound of claim 1, inwhich:R¹ represents a hydrogen atom or a methyl group; l is zero or aninteger 1 or 2; (m+n) is an integer 2, 3, 4, 5 or 6; Y represents asingle bond, an oxygen atom, a sulfur atom or a group of formula R⁸N<wherein R⁸ represents a hydrogen atom, a methyl group, an ethyl group,a formyl group or an acetyl group, R² represents a hydrogen atom, afluorine atom, a hydroxy group, a methoxy group, an ethoxy group, anamino group, an acetamido group, an acetoxy group, a formyl group, anacetyl group, a carboxy group, a methoxycarbonyl group, anethoxycarbonyl group, a cyano group, a group of formula --CONR⁶ R⁷,wherein:R⁶ and R⁷ are independently selected form the group consistingof hydrogen atoms, C₁ -C₃ alkyl groups, allyl groups, propargyl groupsand alkyl groups having at least one substituent selected from the groupconsisting of substituents (a), defined in claim 1, or R⁶ and R⁷together represent a group of formula --(CH₂)₃ --, --(CH₂)₄ --, --(CH₂)₅--, --(CH₂)₂ OCO₂ --, --(CH₂)₂ O(OH₂)₂ --, --(CH₂)₂ NR⁸ (CH₂)₂ --,wherein;R⁸ represents a hydrogen atom, or a methyl, formyl or acetylgroup, --(CH₂)₂ SCH₂ -- or --(CH₂)₂ S(CH₂)₂ --, a group of formula--S(O)_(j) R⁹, wherein:j is zero or an integer 1 or 2 and R⁹ representsa methyl, ethyl or propyl group, a methyl group, an ethyl group or apropyl group; the substituent on the alkyl group in R³ and R⁴ is ahydroxy, cyano, carbamoyl, carboxy or nitro group, or a fluorine orchlorine atom, or a methoxy, ethoxy, acetyl, formyl, acetoxy,acetylamino, formylamino, methoxycarbonyl or ethoxycarbonyl group, or agroup of formula --NR¹⁰ R¹¹, wherein:R¹⁰ and R¹¹ are independentlyselected from the group consisting of hydrogen atoms, methyl groups andethyl groups, a group of formula --CONR¹² R¹³, wherein:R¹² and R¹³ areindependently selected from the group consisting of hydrogen atoms,methyl groups and ethyl groups, a group of formula --SO₂ NR¹⁴ R¹⁵,wherein:R¹⁴ and R¹⁵ are independently selected from the group consistingof hydrogen atoms, methyl groups and ethyl groups, a group of formula--S(O)_(t) R¹⁶, wherein:t is zero or an integer 1 or 2 and R¹⁶represents a methyl group, a group of formula --NHSO₂ R¹⁷, wherein:R¹⁷represents a methyl or ethyl group, a group of formula --N═CR¹⁸ NR¹⁹ R²⁰or --NR²¹ CR²² ═NR²³, wherein:R¹⁸ to R²³ are independently selected fromthe group consisting of hydrogen atoms, methyl groups and ethyl groups,or a group of formula --C(═NH)NR²⁴ R²⁵, wherein:R²⁴ and R²⁵ areindependently selected from the group consisting of hydrogen atoms,methyl groups and ethyl groups; R³ and R⁴ are independently selectedfrom the group consisting of methyl, ethyl, propyl, allyl, propargyl,benzyl and cyclopropylmethyl groups, or together with R² represent agroup of formula --(CH₂)₂ --, --(CH₂)₃ --, --(CH₂)₄ --, --(CH₂)₅ --,--(CH₂)--O--, --(CH₂)₂ --OCH₂ --, --(CH₂)--O--(CH₂)₂ --, --CH₂)--NR⁸ --,--(CH₂)₂ --NR⁸ CH₂ --, --(CH₂)₂ --NR⁸ --(CH₂)₂ --, wherein:R⁸ representsa hydrogen atom or a methyl, ethyl, formyl or acetyl group,--(CH₂)--S--, --(CH₂)₂ --SCH₂ -- or --(CH₂)₂ --S--(CH₂)₂ --; and whereR⁶ together with R⁷ represents an alkylene group which is substituted oreither R³ or R⁴ together with R² represents an alkylene group which issubstituted, the substituent is a methyl or ethyl group, a fluorineatom, a hydroxy group or an oxo group.
 5. The compound of claim 1,wherein the 1-hydroxyethyl group at the 6-penem position is in the1(R)-hydroxyethyl configuration.
 6. The compound of claim 1, wherein R¹represents a hydrogen atom, and the penem system has the (5R, 6S)configuration.
 7. The compound of claim 1, wherein R¹ represents amethyl group, and the penem system has the (1R, 5S, 6S) configuration.8. The compound of claim 1, wherein the compound is2-(2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 9. The compound of claim1, wherein the compound is (1R, 5S, 6S)-2-((2S,4S)-2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 10. The compound of claim1, wherein the compound is2-(2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 11. The compound of claim1, wherein the compound is (5R, 6S)-2-((2S,4S)-2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 12. The compound of claim1, wherein the compound is2-(1,1-dimethyl-2-dimethylcarbamoylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 13. The compound of claim1, wherein the compound is (1R, 5S, 6S)-2-((2S,4S)-1,1-dimethyl-2-dimethylcarbamoylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 14. The compound of claim1, wherein the compound is2-(1,1-dimethyl-2-ethylcarbamoylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 15. The compound of claim1, wherein the compound is (1R, 5S, 6S)-2-((2S,4S)-1,1-dimethyl-2-ethylcarbamoylpyrrolidinium-4-ylthio)-6-((1R-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 16. The compound of claim1, wherein the compound is2-(2-cyclopropylcarbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 17. The compound of claim1, wherein the compound is (1R, 5S, 6S)-2-((2S,4S)-2-cyclopropylcarbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylateor a pharmaceutically acceptable salt thereof.
 18. A pharmaceuticalcomposition comprising an effective amount of an antibiotic in admixturewith a pharmaceutically acceptable carrier or diluent, wherein theantibiotic is at least one compound selected from the group consistingof compounds of formula (I) and a pharmaceutically acceptable saltthereof, as defined in claim
 1. 19. The composition of claim 18,wherein:R¹ represents a hydrogen atom or a methyl group; l is zero or aninteger 1 or 2; (m+n) is an integer 2, 3, 4, 5 or 6; Y represents asingle bond, an oxygen atom, a sulfur atom or a group of formula R⁸N<wherein R⁸ represents a hydrogen atom, a methyl group, an ethyl group,a formyl group or an acetyl group; R² represents a hydrogen atom, afluorine atom, a hydroxy group, a methoxy group, an ethoxy group, anamino group, an acetamido group, an acetoxy group, a formyl group, anacetyl group, a carboxy group, a methoxycarbonyl group, anethoxycarbonyl group, a cyano group, a group of formula --CONR⁶ R⁷,wherein:R⁶ and R⁷ are independently selected from the group consistingof hydrogen atoms, C₁ -C₃ alkyl groups, allyl groups, propargyl groupsand alkyl groups having at least one substituent selected from the groupconsisting of said substituents (a), or R⁶ and R⁷ together represent agroup of formula --(CH₂)₃ --, --(CH₂)₄ --, --(CH₂)₅ --, --(CH₂)₂ OCH₂--, --(C₂)₂ O(OH₂)₂ --, --(CH₂)₂ NR⁸ (CH₂)₂ --, wherein:R⁸ represents ahydrogen atom, or a methyl, formyl or acetyl group, --(CH₂)₂ SCH₂ -- or--(CH₂)₂ S(CH₂)₂ --, a group of formula --S(O)_(j) R⁹, wherein:j is zeroor an integer 1 or 2 and R⁹ represents a methyl, ethyl or propyl group,a methyl group, an ethyl group or a propyl group; the substituent on thealkyl group in R³ and R⁴ is a hydroxy, cyano, carbamoyl, carboxy ornitro group, or a fluorine or chlorine atom, or a methoxy, ethoxy,acetyl, formyl, acetoxy, acetylamino, formylamino, methoxycarbonyl orethoxycarbonyl group, or a group of formula --NR¹⁰ R¹¹, wherein:R¹⁰ andR¹¹ are independently selected from the group consisting of hydrogenatoms, methyl groups and ethyl groups, a group of formula --CONR¹² R¹³,wherein:R¹² and R¹³ are independently selected from the group consistingof hydrogen atoms, methyl groups and ethyl groups, a group of formula--SO₂ NR¹⁴ R¹⁵, wherein:R¹⁴ and R¹⁵ are independently selected from thegroup consisting of hydrogen atoms, methyl groups and ethyl groups, agroup of formula --S(O)_(t) R¹⁶ , wherein:t is zero or an integer 1 or 2and R¹⁶ represents a methyl group, a group of formula --NHSO₂ R¹⁷,wherein:R¹⁷ represents a methyl or ethyl group, a group of formula--N═CR¹⁸ NR¹⁹ R²⁰ or --NR²¹ CR²² ═NR²³, wherein:R¹⁸ to R²³ areindependently selected from the group consisting of hydrogen atoms,methyl groups and ethyl groups, or a group of formula --C(═NH)NR²⁴ R²⁵ ,wherein:R²⁴ and R²⁵ are independently selected from the group consistingof hydrogen atoms, methyl groups and ethyl groups; R³ and R⁴ areindependently selected from the group consisting of methyl, ethyl,propyl, allyl, propargyl, benzyl and cyclopropylmethyl groups, ortogether with R² represent a group of formula --(CH₂)₂ --, --(CH₂)₃ --,--(CH₂)₄ --, --(CH₂)₅ --, --(CH₂)--O--, --(CH₂)₂ --OCH₂ --,--(CH₂)--O--(CH₂)₂ --, --(CH₂)--NR⁸ --, --(CH₂)₂ --NR⁸ CH₂ --, --(CH₂)₂--NR⁸ --(CH₂)₂ --, wherein:R⁸ represents a hydrogen atom or a methyl,ethyl, formyl or acetyl group, --(CH₂)--S--, --(CH₂)₂ --SCH₂ -- or--(CH₂)₂ --S--(CH₂)₂ --; and where R⁶ together with R⁷ represents analkylene group which is substituted or either R³ or R⁴ together with R²represents an alkylene group which is substituted, the substituent is amethyl or ethyl group, a fluorine atom, a hydroxy group or an oxo group.20. The composition of claim 18, wherein the antibiotic is selected fromthe group consistingof:2-(2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;2-(2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-carbapen-2-em-3-carboxylate;2-(1,1-dimethyl-2-dimethylcarbamoylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;2-(1,1-dimethyl-2-ethylcarbamoylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;2-(2-cyclopropylcarbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;anda pharmaceutically acceptable salt thereof.
 21. The composition of claim18, wherein the antibiotic is selected from the group consisting of:(1R,5S, 6S)-2-((2S,4S)-2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;(5R, 6S)-2-((2S,4S)-2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-carbapen-2-em-3-carboxylate;(1R, 5S, 6S)-2-((2S,4S)-1,1-dimethyl-2-dimethylcarbamoylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;(1R, 5S, 6S)-2-((2S,4S)-1,1-dimethyl-2-ethylcarbamoylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;(1R, 5S, 6S)-2-((2S,4S)-2-cyclopropylcarbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;anda pharmaceutically acceptable salt thereof.
 22. A method for thetreatment of prevention of microbial infection by the administration toa mammal of an effective amount of an antibiotic, wherein the antibioticis at least one compound selected from the group consisting of compoundsof formula (I) and a pharmaceutically acceptable salt thereof, asdefined in claim
 1. 23. The method of claim 22, wherein:R¹ represents ahydrogen atom or a methyl group; l is zero or an integer 1 or 2; (m+n)is an integer 2, 3, 4, 5 or 6; Y represents a single bond, an oxygenatom, a sulfur atom or a group of formula R⁸ N<wherein R⁸ represents ahydrogen atom, a methyl group, an ethyl group, a formyl group or anacetyl group; R² represents a hydrogen atom, a fluorine atom, a hydroxygroup, a methoxy group, an ethoxy group, an amino group, an acetamidogroup, an acetoxy group, a formyl group, an acetyl group, a carboxygroup, a methoxycarbonyl group, an ethoxycarbonyl group, a cyano group,a group of formula --CONR⁶ R⁷, wherein:R⁶ and R⁷ are independentlyselected from the group consisting of hydrogen atoms, C₁ -C₃ alkylgroups, allyl groups, propargyl groups and alkyl groups having at leastone substituent selected from the group consisting of said substituents(a), or R⁶ and R⁷ together represent a group of formula --(CH₂)₃ --,--(CH₂)₄ --, --(CH₂)₅ --, --(CH₂)₂ OCH₂ --, --(C₂)₂ O(OH₂)₂ --, --(CH₂)₂NR⁸ (CH₂)₂ --, wherein:R⁸ represents a hydrogen atom, or a methyl,formyl or acetyl group, --(CH₂)₂ SCH₂ -- or --(CH₂)₂ S(CH₂)₂ --, a groupof formula --S(O)_(j) R⁹, wherein:j is zero or an integer 1 or 2 and R⁹represents a methyl, ethyl or propyl group, a methyl group, an ethylgroup or a propyl group; the substituent on the alkyl group in R³ and R⁴is a hydroxy, cyano, carbamoyl, carboxy or nitro group, or a fluorine orchlorine atom, or a methoxy, ethoxy, acetyl, formyl, acetoxy,acetylamino, formylamino, methoxycarbonyl or ethoxycarbonyl group, or agroup of formula --NR¹⁰ R¹¹, wherein:R¹⁰ and R¹¹ are independentlyselected from the group consisting of hydrogen atoms, methyl groups andethyl groups, a group of formula --CONR¹² R¹³, wherein:R¹² and R¹³ areindependently selected from the group consisting of hydrogen atoms,methyl groups and ethyl groups, a group of formula --SO₂ NR¹⁴ R¹⁵,wherein:R¹⁴ and R¹⁵ are independently selected from the group consistingof hydrogen atoms, methyl groups and ethyl groups, a group of formula--S(O)_(t) R¹⁶ , wherein:t is zero or an integer 1 or 2 and R¹⁶represents a methyl group, a group of formula --NHSO₂ R¹⁷, wherein:R¹⁷represents a methyl or ethyl group, a group of formula --N═CR¹⁸ NR¹⁹ R²⁰or --NR²¹ CR²² ═NR²³, wherein:R¹⁸ to R²³ are independently selected fromthe group consisting of hydrogen atoms, methyl groups and ethyl groups,or a group of formula --C(═NH)NR²⁴ R²⁵ , wherein:R²⁴ and R²⁵ areindependently selected from the group consisting of hydrogen atoms,methyl groups and ethyl groups; R³ and R⁴ are independently selectedfrom the group consisting of methyl, ethyl, propyl, allyl, propargyl,benzyl and cyclopropylmethyl groups, or together with R² represent agroup of formula --(CH₂)₂ --, --(CH₂)₃ --, --(CH₂)₄ --, --(CH₂)₅ --,--(CH₂)--O--, --(CH₂)₂ --OCH₂ --, --(CH₂)--O--(CH₂)₂ --, --(CH₂)--NR⁸--, --(CH₂)₂ --NR⁸ CH₂ --, --(CH₂)₂ --NR⁸ --(CH₂)₂ --, wherein:R⁸represents a hydrogen atom or a methyl, ethyl, formyl or acetyl group,--(CH₂)--S--, --(CH₂)₂ --SCH₂ -- or --(CH₂)₂ --S--(CH₂)₂ --; and whereR⁶ together with R⁷ represents an alkylene group which is substituted oreither R³ or R⁴ together with R² represents an alkylene group which issubstituted, the substituent is a methyl or ethyl group, a fluorineatom, a hydroxy group or an oxo group.
 24. The method of claim 22,wherein the antibiotic is selected from the group consistingof:2-(2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;2-(2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-carbapen-2-em-3-carboxylate;2-(1,1-dimethyl-2-dimethylcarbamoylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;2-(1,1-dimethyl-2-ethylcarbamoylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;2-(2-cyclopropylcarbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-(1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;anda pharmaceutically acceptable salt thereof.
 25. The method of claim 22,wherein the antibiotic is selected from the group consisting of:(1R, 5S,6S)-2-((2S,4S)-2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;(5R, 6S)-2-((2S,4S)-2-carbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-carbapen-2-em-3-carboxylate;(1R, 5S, 6S)-2-((2S,4S)-1,1-dimethyl-2-dimethylcarbamoylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;(1R, 5S, 6S)-2-((2S,4S)-1,1-dimethyl-2-ethylcarbamoylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;(1R, 5S, 6S)-2-((2S,4S)-2-cyclopropylcarbamoyl-1,1-dimethylpyrrolidinium-4-ylthio)-6-((1R)-1-hydroxyethyl)-1-methyl-1-carbapen-2-em-3-carboxylate;anda pharmaceutically acceptable salt thereof.
 26. The method of claim 22,wherein the antibiotic is administered orally.
 27. The method of claim22, wherein the antibiotic is administered parenterally.